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



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.


Only Threes and Layups

By Kindred Winecoff

I love this. I’ve thought for awhile that most teams should shoot way more 3s and never attempt a 2 point shot past 6-8 feet. The math is really straightforward: a 23′ shot is worth 50% more than a 22′ shot while the odds of success are basically equivalent. The only shot with a greater than 50% average is a layup/dunk so why attempt low-percentage 2 pointers?

I despise Coach K, but he has had arguably the most successful college coaching career by doing two things: putting a decent-to-good 3 point shooter at all four corners on offense and getting his guys to take charges on defense (flopping if necessary). It’s a simple formula. You don’t gotta have Lebron to make that a winning strategy… just Ryan Kelly. Of course if you do have Lebron, or even Austin Cook, spacing the floor gives him opportunities to drive and get layups. Meanwhile, having players crash the boards from the perimeter opens up offensive rebounding lanes for easy putbacks, so some of those missed 3 attempts will lead to layups or dunks.

You don’t need to run some crazy offensive or defensive scheme. Just get guys who can hit 1/3 of their shots from distance and/or drive. If more teams actually started doing this the rules of the game might need to be changed again.

NBA teams are finally starting to get smart. It’s taken awhile, but it’s happening.

The Difference Between Relative and Absolute Difference

By Graham Peterson

20091118-no-pumpkin-pieAsk just about any economist if she believes economic growth trumps the concerns people have about relative inequality, and she will say yes.  Why is that?  Well, no matter how big the difference between your slice and my slice of the pie is, if the pie is growing — both of our slices are getting bigger.  So pull up to a low-cal sliver of GDP!

Now that doesn’t stop economists from studying relative inequality (no, they don’t just legitimate neoluburil hegermany).  And so too for other social sciences, paying attention to the difference between absolute outcomes within-group (slice expansion) shouldn’t stop us from paying attention to the difference between relative outcomes between-group (slice envy — try some slice Viagra?).

Take an example.  The Huffington Post has reliably delivered another sex survey, and found that Australian men lie in bed more than Australian women.  It’s a cute finding.  We’ll leverage this cuteness to reason over the differences between relative and absolute social outcomes — without the distracting ethical baggage — because these outcomes get a lot more important when we approach matters like relative racial outcomes.

So check this out: 25.4% of Australian men admit to fibbing the “I love you” during sex versus 6.1% of women.  Eek.  Men lie when they say a sweaty “I love you” MORE THAN FOUR TIMES as often as women (the relative difference).  But don’t forget to evaluate the absolute occurrence of the behavior, which is quite low: 74.6% of men, and 94% of women, are being honest in bed.  That’s the great majority.  This is a check one should always perform as they evaluate their ethical and political feelings about a social fact.  More importantly, it’s a crucial check for evaluating the social scientific significance of studying X.

If relative differences between groups are large, but the absolute occurrence of that outcome is small — there are just bigger fish to fry.  Lots of relative-variation studiers, like sociologists say, report on how “blacks end up in Y at two times the rate of whites.”  Sure, if 2% of blacks end up in Y, against 1% of whites, that’s certainly true.  But that still means we’re picking fights and investing resources into the study of something that 98.5% of the entire population don’t struggle with.

Every relative difference between groups is not born equal.  So no, the mere existence of one or another troubling social phenomenon does not deserve equal attention.  That is, unless, you would jump onto a subway track to save both a mouse or your son.  Think about it: “Today NBC 5 reports that a clerk was shot to death on the 1400 block of Milwaukee Ave. [and billions of people all over the world had a mostly peaceful day with one another].”  Successful social coordination, progress, and the often times strikingly low incidence of malevolence and misery, deserve our attention.