Kamikaze Attacks by the Numbers: A Statistical Analysis of Japan’s Wartime Strategy

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Note: This is a guest post by Dave Hackerson.

One of the defining symbols of the vicious struggle between the US and Japan in the Pacific War, this word always conjures up a conflicting mix of emotions inside me. The very word “kamikaze” has become a synonym for “suicide attack” in the English language. The way WW2 was taught in school (in America) pretty much left us with the impression that kamikaze attacks were part of the standard strategy of the Japanese Imperial Army and Navy throughout the entire war. However, it was only recently that I was surprised to learn that the first time the Japanese introduced this strategy was on October 25, 1944 during the second Battle of Leyte Gulf. The Mainichi Shinbun here in Japan put together a wonderful collection to commemorate the 70th anniversary of this strategy. It features data that has not only been debated and analyzed from a number of angles, but it also provides statistical evidence that underscores the utter failure of this strategy. The title of the article is “Did the divine wind really blow? ‘Special strikes’ claim lives of 4000,” and it is the second part of a three part series called “Numbers tell a tale—Looking at the Pacific War through data”. The first part was posted in mid-August, and the third and final part is due to be put online in December. The original Japanese version for this special can be accessed here. The slides I refer to numbers “1” to “5” listed at the very bottom of each page. The current slide is the one highlighted in blue.

In this post, I will provide an overview of the information on this site while occasionally inserting my own analysis and translations of select quotes. I hope it helps to paint a clearer picture of a truly flawed strategy that is still not properly understood by both sides.

Slide 1

True to the series name, this article wastes no time in hitting you with some pure, raw data. The first pie graph (11%, 89%) indicates the actual success rate of kamikaze attacks. As you can see from the graph, only 11% were successful, while the remaining 89% ended in failure. This means that merely 1 in 9 planes actually hit their targets. After introducing these figures, the article focuses on the initial execution of the kamikaze strategy during the Second Battle of Leyte Gulf on October 25, 1944. Five planes hit and sunk the escort carrier USS St. Lo, while other planes succeeded in damaging five other ships. The estimated success rate in this battle was 27%.

The article then puts this percentage into context by comparing it to the success rate of dive bomb attacks (non-kamikaze) in other battles. Here are the figures:

Pearl Harbor (1941): 58.5%

Battle of Ceylon (1942): 89% (percentage of hits on the British carrier HMS Hermes)

Coral Sea (1942): 53% (percentage of hits on the USS Lexington, which was severely damaged)

Looking at these figures, it’s clear that the kamikaze attacks were not that effective. The Japanese navy was overly optimistic and believed they would be fairly successful, but the US quickly adapted, and by the end of the war the success rate fell to 7.9% (Battle of Okinawa). Even the Dai Honei (main headquarters of the Japanese forces) admitted that the attacks had little to no effect.

The next part of the article is titled “War of attrition: ‘Certain death’ strategy that claims both aircraft and pilots”. It discusses the reasons why the hit rate for Japanese air force dropped so dramatically as the war wore on. Here are the three reasons cited.

  • Decline in the flying abilities of the fighter pilots
  • Deteriorating performance of aircraft and materials
  • Improvements in American countermeasures

After introducing these reasons, the article makes a very important statement. “Kamikaze attacks meant that you lost both the aircraft and pilots. This not only wore down Japan’s fighting strength, but essentially destroyed the nation’s capacity to actually wage war in the future.”

The article then turns its attention back to the first kamikaze attack and the pilot chosen to lead it. Lieutenant Yukio Seki was a graduate of the naval academy and proven veteran. He died crashing his plane into the USS St. Lo and was later enshrined as a “軍神 (gun-shin, or military god)” in Yasukuni Shrine. The article seems to imply that this “honor” is actually an injustice to the Seki’s memory in light of what he said before heading into battle. “I’m fully confident that I can drop a bomb on any aircraft during a normal attack. Japan’s screwed if it’s ordering a pilot like me to smash his craft into an enemy vessel.” These words are in stark contrast to the quote and images on the cover photo of Shashin Shuuhou (Photographic Weekly, a morale boosting propaganda magazine published from the mid-1930s until mid-1945) that accompanies this post. The main quote shown to the left of the Lieutenant Seki states: “A single vessel strikes true in defense of the land of gods. Oh, our Kamikaze (Divine Wind) Special Strike Force. Your fidelity will shine radiantly for the next 10,000 generations.” The quote in the bottom right further contradicts the statement Sergeant Seki made before he took off. “Lieutenant Seki, commander of the Shikijima Battalion that served as the First Kamikaze Special Strike Force Battalion to be sent out on an all-out bomb strike. Immediately before heading into battle, Lieutenant Seki is said to have rallied his troops with the following cry: ‘Men, we are not members of a bomber squad. We are the bombs. Now up and away with me!’”

Slide 2

The focus then shifts its attention to the heavy losses among the ranks of Japanese pilots. The Japanese navy started with 7000 well-trained pilots at the beginning of the war. By 1944 over 3900 had died in battle. In the early days of the war the Allies estimated that Japanese pilots had a 6-1 superiority advantage over Allied pilots, but by April of 1943 it was even at 1-1. Japan simply could not replace the pilots it lost at a sufficient pace, so it decided to compensate by “short-tracking” their training. The pie graph here is really telling.

Rank A pilots (over 6 months of flight training): 16.3%

Rank B pilots (4 to 6 months of flight training): 14.4%

Rank C pilots (approx. 3 months of flight training): 25%

Rank D pilots (less than 3 months, or in some cases only flight theory): 44.3%

These figures are breakdown of the pilots sent to fight in the Battle of Okinawa in 1945. The article then cites three reasons believed to have initiated a vicious cycle for the Japanese navy:

  1. Compensate loss in air force manpower by short-tracking training and sending raw pilots straight into the fight
  2. Raw pilots have a low chance of returning from battle, and most likely fail to influence the course of battle
  3. Losses only increase, while the ranks of pilots continue to thin.

The authors of the article squarely place the blame on the shoulders of the upper brass in the navy. Personally, I think the Japanese navy would not have sunk to such desperate measures if Admiral Yamamoto hadn’t been shot down and killed in 1943. He would have found a way to prolong the fight and preserve Japan’s precious little resources. One could argue that the U.S.’s decision to shoot down Yamamoto and take him out of the picture eliminated the voice of reason within the Japanese ranks, and actually paved the way for this strategy to be adopted.

The article implies that Japan was insane for throwing away what little resources it had. When the enemy has 10 times the amount of resources, you do everything you can to hold onto what you have. The Japanese brass seemingly defied this logic by not only wasting aircraft, but needlessly wasting human lives. But why would they do that? Japanese writer Kazutoshi Hando, a man who has written extensively about the Showa Period and WW2, provides some valuable insight into how these men thought. “The very concept of logistics was either given little thought or entirely ignored by the Japanese military… After all, in the eyes of the Army’s General Staff Office and the commissioned officers in the navy, troops were ultimately viewed no more as resources that could be gathered for a mere 1 sen 5 ri (price for a postcard at that time). When they formulated a strategy, they flung the troops out to the front with 6 go (about 900 grams) of rice and a 25 kilogram pack. If you ran out of food, you were told to forage for your own supplies wherever you were. Surrender wasn’t option (because it was actually prohibited under the Japanese military code), so if you found yourself in a losing battle, the only option was gyokusai (a figurative term coined by the Japanese military which loosely translates as “beautiful death”). They didn’t give any thought whatsoever to potential survivors.”

Not only were the majority of the pilots deployed in the latter the days of the war vastly inferior, but the aircraft deployed were also no match for the Allied forces. In addition to fighters and bombers, reconnaissance and even practice planes were deployed! As the war wore on, Japan faced these problems:

  • Lack of skilled engineers, resulting in the low performance of new aircraft because of the deterioration in manufacture and production quality.
  • Use of low octane, poor quality fuel.

In spite of all these problems, the Japanese armed forces went ahead with this strategy. The navy asked for the construction of aircraft that would save on materials, be easy to fly in training, and able to conserve fuel. Unfortunately, the end product was of inferior quality compared to the aircraft produced in the early days of the war. Combined with poorly trained pilots, it was simply a disaster waiting to happen.

Slide 3

This slide focuses on the performance capacity of the aircraft. Lots of info on plane specs, but as you can see, by the end of the war Allied aircraft were simply far superior to Japanese planes in every respect. The kanji 零 in the name of the plane 零式艦上戦闘機 21型 indicates “rei” or “zero” (Type Zero Carrier Fighter 21). Click and hold the mouse cursor on the plane to rotate the view. The specs of the Zero changed very little during the war. The first generation of Zero fighters (1939) carried a Sakae 21 Engine, which boasted 950 hp. The type produced after 1943 was fitted with the Sakae 52 Engine that delivered 1100 hp, an improvement of only 150 hp, and a top speed of 624 km/h. A seasoned pilot would have had his hands full going up against the likes of the USAF Hellcats and P51s, but with the green pilots the Japanese forces sent up it was clear they no longer carried about fighting for air superiority.

Slide 4

I won’t get into the details here, but this slide reveals how quickly the US adapted to the kamikaze attacks. Surprising as this may sound, these attacks failed to sink any major ships or carriers. This is because the US used radar effectively to scramble fighters to meet the Japanese attacks. In addition, the US had damage control units on board each ship, so even if a kamikaze pilot broke through, the damage could be contained right away, enabling the craft to stay in the fight. While many ships were damaged, less than 50 were actually sunk. The chart here is quite telling. The red bars indicate ships sunk, and the yellow bars indicate ships damaged, but not sunk.

Slide 5

This slide takes an indirect jab at people who attempt to beautify the sacrifices made by kamikaze pilots. The vast majority did not want to participate in the attacks. Saburo Sakai, one of Japan’s ace pilots, commented on how the strategy lowered morale. “The morale sunk”, he said. “Even if the reasons for fighting mean that you have only a 10 percent chance of coming back, you’ll fight hard for that. The guys upstairs (upper brass) claim morale went up. That’s a flat-out lie.”

There were even instances of NCOs ordering their men not to do kamikaze attacks, and instead instructed them to conduct “normal attacks”. In an interview linked to this article, the non-fiction writer Masayasu Hosaka speaks about reading the memoirs of someone who witnessed the pilots flying off to do their kamikaze attack. This witness states that the radios of all the aircraft were kept on, so they could actually hear everything the pilots said, including the statements they uttered right before they met their end. Here are some of the things kamikaze pilots said: “F*ing navy aholes!” , “Oh Mother!”, or the name of their wives or sweethearts. It seems that very few shouted “Banzai Japanese Empire” (“Banzai” means “10,000 years”).

Returning to the question originally posed in the title of the article, it is almost assuredly clear that the divine wind never blew. There wasn’t even much of a breeze. In adding my own two cents, the kamikaze attacks were a great propaganda tool for the US, for it allowed us to portray the enemy as fanatical and beyond reason. This made it easy for us to justify the atomic bombings, especially after the war, because the kamikaze attacks seemingly “proved” that only excessive measures would bring them to the negotiation table. The propaganda twist on kamikaze tactics was carried over into post-war education in the US, and led many of us (or at least myself when I was a kid) to believe that Japanese soldiers were possessed with an unswerving conviction to fight to the death.

In closing, I once again borrow the words of Kazutoshi Hando. He cuts straight to the chase:

The complete irresponsibility and stupidity of the nation’s military leaders drove the troops to their deaths. The same can be said for the kamikaze special strike force strategy. They took advantage of the unadulterated feelings of the pilots. People claim it’s a form of ‘Japanese aesthetics’, but that’s pure nonsense. The General Staff Office built it up as some grand strategy when in actuality they sat at their desks merely playing with their pencils wondering ‘how many planes can we send out today?’ This lot can never be forgiven.


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9 thoughts on “Kamikaze Attacks by the Numbers: A Statistical Analysis of Japan’s Wartime Strategy

  1. Excellent article. I’m glad those Japanese Soldiers then exhibited some of the same feelings toward their out-of-toudh brass that we have in this era.

  2. Whatever Admiral Yamamoto’s capabilities I do not believe he would have avoided the losses. The Japanese had no obviously better alternatives (other than immediate surrender) and were operating in an absence of good information to guide policy. If they didn’t commit their air forces to confront the US they knew their ships would be sunk and their ground forces would be isolated with no supplies. Further while they were suffering tremendous losses, the reports from the fronts suggested that the US was suffering even greater losses. While internal discussions among the high command indicated that some thought that the reports were likely exaggerated, none, at least publicly, recognized that the (late war) US loss estimates were often off by about a factor of ten. While the 42 and early 43 reports were not that exaggerated, they were still very misleading.
    Yamamoto after Pearl Harbor consistently sought another decisive victory that would convince the US to give up the fight, Instead Japan suffered one decisive defeat, and a number of other (less decisive) battles that drained Japan’s forces faster than they could be replaced. In the end, rather that retain his carrier aircrews for the replacement carriers due to arrive in early 44, he committed them to ground based operations in order to strike at Guadalcanal, protect the Tokyo express from Henderson Field, and disrupt US naval operations. By the time he was killed the IJN air force was already a shadow of its early 42 capabilities.
    By late 44 the kamikaze operations were Japan’s, best, albeit poor, hope. At the battles of the Philippine Sea and Formosa, less than 1% of the attacking Japanese Air Forces were able to inflict damage on the US fleet, and the success per sortie was much less than 1%. They were little better in the initial US invasion of the Philippines. While only 1/9 of the kamikaze air sorties resulted in damage, a significant fraction would return to base due to bad weather, mechanical problems, the US fleet being out position, or pilot discretion once in the air. Japanese records suggest a little over 1900 kamikaze sorties during the Okinawa campaign, but allied records visually identified less than 1000 as reaching the combat zone. Of the ones that were identified as reaching the combat zone, about half were shot down by aircraft, half of the remainder by the ship guns, and a small percentage crashed without hitting a ship for no obvious reason. Unfortunately for the Japanese, kamikaze missions losing half their force per sortie with a ten percent chance per sortie of causing damage, were still better than conventional missions loosing a third of its force per sortie with less than a 1% chance of causing damage. The Japanese pilot’s confidence that they would have been more effective on conventional missions was misplaced. (Note that over Okinawa ever five kamikazes was intended to be accompanied by two fighters to protect from initial allied intercepts, and there were a number of conventional missions also flown.)

    1. Thank you for the nice comment William, and raising a number of good points.

      It is ironic that Japan’s success at Pearl Harbor essentially proved that the age of the battleship was over, yet the IJN insisted on organizing its fleet around massive battleships like the Musashi and Yamato (the latter of which cost nearly 3% of Japan’s GDP to build). Yamamoto may not have been able to avoid the losses, but I don’t think he would have resorted to the kamikaze air sorties (or naval kamikaze strikes such as the Kaiten single-man submarines). As you indicated, though, it is hard to imagine any other viable alternatives. His tactical decisions to commit to striking the US at Guadacanal aside, Yamamoto knew from before the start of the war that there would be only one conclusion to that fight, as revealed by the following quote he made to his superiors: “The way I see it, I can wreak havoc on the waves for about a year to a year and a half. Beyond that I can make no guarantees whatsoever about our prospects.”

      Yamamoto’s insistence on trying to win a decisive battle reveals a major strategic flaw that was prevalent throughout the entire ranks of the IJN’s upper brass. This flaw emerged, or rather was the byproduct of the IJN’s decisive victory over Imperial Russia’s Baltic Fleet in the Russo-Japanese War. That victory helped to provide them with leverage at the negotiation table, and the US (or more specifically Teddy Roosevelt) helped them secure favorable terms. While Japan was involved in WW1, it operated almost exclusively in Asia and thus did not directly experience the true nature of what proved to be the first “total war” (though some may argue we saw signs of that in the American Civil War). The Allies ultimately prevailed not as a result of decisive victories in the field, but because domestic developments back on the German homefront essentially prevented it from carrying on the fight. Japanese military command and politicians were slow to recognize that the rules of warfare had changed, and did not fully understand what implications of “total war” meant. One of the few people who did was Kanji Ishihara, but political infighting resulted in him being kept from taking an active part in the strategy formulation process.

  3. Great article + follow up comments

    It is great to see evidence on this front. At the start of the war the Japanese swept through colonial and Chinese opposition. But by the end of the war it was an utter massacre. As per the article, the decisions on Kamikaze and Banzai attacks effectively lined up their troops to be effectively shot at will.

    Utter madness….

  4. I have an issue with the fact that “the radios of all the aircraft were kept on, so they could actually hear everything the pilots said, including the statements they uttered right before they met their end.”

    If you leave several radios emitters on at the same time, you can’t hear anything but garbage. On top of that the pilots would not have been able to hear the instructions given to them regarding the coordination of the attack (as a radio can emit or receive, but not both at the same time), so the credibility of this witness is to be verified, which unfortunately bring a shade of doubt to this article which is otherwise very well written.

    1. David A.

      Thanks for taking the time to read this and your comment regarding the radio. I went back and checked the original Japanese article that I read in preparing this article, and the witness in question was apparently a staff officer. Here’s that article in Japanese, with a picture of the radio the staff officer was supposedly referring to.


      The staff officer could have perhaps been trying to show that he sympathized with the men who died and indirectly show that he did not approve of the attacks.

    2. I did a little more digging on the radio issue and found that the author did not do a good job of presenting the quote of the witness. He used the word 無線機 (musenki) in Japanese, which loosely translates to “radio”, but the type of radio indicated must be derived from context. In conveying the quote, he clearly states “hear”, but this was apparently a mistake on his part. In the discussions that I read online, the radio used was for transmitting telegraphic messages. Each plane supposedly had its own unique and original identification code, and when that pilot stop sending that code, the staff officers back at the base judged that pilot to be dead. In some cases where larger aircraft were used and multiple people were on board, they sent longer messages in Morse code, and it appears the content of these messages were discussed in advance. So, in getting back to the quote, the author should have said something like “the reports sent in read AA”, not “heard”. I hope this helps to clear up the radio issue for you.

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