http://tinyurl.com/4xo2fj
by Josh Kalk
April 15, 2008
The Royals' Brian Bannister is off to a tremendous start for the Kansas City
Royals. I mentioned him in my last article, saying that not a lot of people
thought he could repeat his excellent season last year. The main reason was
that he wasn't striking out enough batters compared to the number he walked.
Last year, his ERA checked in at a cool 3.87 but his FIP was a more mediocre
4.52. This is mostly from his K/G being a mere 4.4 and his BB/G of 2.5. Now
2.5 walks per game isn't bad at all, but only 4.4 strikeouts generally is going
to lead you into danger. So how has he turned it around this year so far?
Well, first he has kept his walk rate at 2.5 BB/G but has upped his strikeouts
to 6.5 per game. That is a huge increase and while he probably shouldn't have
an ERA under one, his FIP is an excellent 2.59 so far. His microscopic ERA of
0.86 has certainly been helped by a Defensive Efficiency Ratio of .825 behind
him and a LOB percentage of 81.2 While both of these numbers will cool off, he
still could be one of the better pitchers in the majors if he can keep the
strikeouts coming.
So how has he increased those strikeouts? Well, let's take a look at his
PITCHf/x data and see. Here are the raw data straight from Sportvision and
MLBAM.
皇家隊的年輕投手Brian Bannister開季表現優異，我在之前的文章曾經提過很多人對
Bannister今年的表現不是很看好，因為他去年的K/BB值不是很優異。那麼，他今年是怎麼
投出這樣優秀的表現？
來看看數據吧。去年他的ERA是3.87但FIP是4.52，這是因為他的K/BB為4.4/2.5。然而，今
年他將這個數值提升到6.5/2.5，這是相當大的進步。雖然說現在他驚人的0.86 ERA有部份
是因為隊友幫忙和極高的殘壘率，但他的FIP是2.59，表示即使去掉運氣的因素，他仍舊會
是聯盟中最好的投手之一，如果他可以維持他的三振能力的話。
所以，他是怎麼提升三振的？我們來看看他的PITCHf/x data吧。
Wow, that is all over the map. MLBAM has him throwing four different fastballs,
a slider and a curve. Clearly, a few of these are grouping errors. This isn't
too surprising; analyst Dan Fox has mentioned they are still working out the
kinks to the pitch classification system.
哇，看來他會七彩變化球！MLBAM顯示他有四種速球、滑球，還有曲球。當然，有些數據是
有誤差的，畢竟這個系統才剛開始運作，還有許多要修正的地方。
First, let's look at the splitters. While Bannister says he would like to
throw a splitter, I haven't read or seen anything that makes me believe these
are really split-fingered fastballs. They are more likely change-ups, as they
are in the same location as the change-ups he was throwing last year.
先來看splitters吧。雖然Bannister曾說過他認為splitters是很好用的球路，但我覺得這
些數據上的splitters看起來比較像他去年在投的change-ups。
Next, what about those cut fastballs? Bannister's four-seamer lives right on
the edge of being a cut fastball, breaking only 1.84 inches towards a
right-handed batter compared to a ball thrown without spin last year. A good
cut fastball has about the same break, but in the opposite direction, so while
I believe these are truly four-seam fastballs, a few had a little more (less?)
break on them and were classified as cut fastballs. This is one of the problems
with classifying pitches individually instead of grouping them together.
Pitchers who throw a certain pitch that is on the border between two pitches
will most likely be shown as having thrown some of each.
那cutters呢？右上角有些Bannister的速球被歸類為cutter，但仔細觀察可以發現它們的
水平位移卻和一般的cutter相反，我認為這些球路其實只是四縫線速球，只是因為break太
大(小?)而被歸類為cutter。
Next, let's look at the curveballs that have negative horizontal movement
compared to a pitch thrown without spin. These are somewhat disconcerting
pitches because they are moving like a lively screwball would move. Bannister
didn't throw anything like that last year, and what is worse all came in his
start in Detroit. While the PITCHf/x cameras are supposed to be calibrated
better this year, it looks like maybe Detroit's cameras weren't having a great
day. For now, I'd keep them considered as curveballs and assume that they
really aren't breaking in to a right-handed batter.
接下來是曲球。有些曲球有負的水平位移。這裡有一些沒有被正確辨識的球路因為它們的
尾勁看來像screwball。Bannister去年從沒投過這種球，而且這些球全部都是來自對老虎
的那場比賽。看來原因是那天老虎球場的相機運作得不太好。
Last, what about the group of fastballs way over to the left that are being
classified as about half sinkers and half fastballs? This is a very interesting
set of pitches and deserves closer attention.
最後，我們來看看左側那些速球吧。這裡一半是sinkers一半是fastballs？
First, it is important to note that while Bannister also didn't throw any
pitches that looked like this last year, these appear to be real—he threw
several of these pitches in each game he played. This makes it much less likely
that they are due to camera error. So, assuming they are a new pitch, are they
really two seamers (sinkers)? Last year in spring training, Bannister mentioned
that he was working on a two-seamer, but my classifcation algorithm didn't find
any two-seamers last year. It is possible he started using this pitch before
the PITCHf/x cameras were installed and then scrapped it by the time they were
turned on. I can't find any mention of him working on that pitch this spring ,
though.
看來這並不是相機的問題。雖然說Bannister去年也沒投過這些球，但這些球路在每場比賽
都有出現。所以，它們是sinkers嗎？Bannister去年春訓時有說過他要練sinker，但我在
去年的資料中沒有找到他有投過sinker的數據。也許是他在相機裝設前就有用過sinker，
但在之後卻漸漸不再使用。今年春訓也沒有聽說過Bannister要加強這項球路。
I don't think these are two-seamers. First, their vertical movement is around
10 inches, compared to a ball thrown without spin. While some pitchers do have
large vertical movement with their two-seamers, it is rare. Second, he is
throwing this pitch at 89 mph, nearly two mph faster than his regular fastball.
Almost always, when a pitcher throws both a four-seamer and a two-seamer, the
two-seamer is a couple of mph slower than the four-seamer. So if this pitch
isn't a two-seamer, what is it?
我不認為這些是二縫線球。這幾球的垂直位移高達10 inches，只有很少數人投的出來。而
且，這幾球球速也高達89 mph，甚至比他的四縫線球還快。所以，這些應該不會是二縫線
球，吧？
I believe it is just his regular four-seam fastball thrown at a different arm
angle. Here is Bannister's release point by pitch type. I have changed all the
cutters to fastballs and splitters to change-ups, and I am listing all these
new pitches as sinkers on this plot to separate them from the fastballs.
這些應該只是普通的四縫線球，只是出手角度的不同。這裡有Bannister出手角度的圖表
，我已經把之前儀器的錯誤糾正過來，把cutter調整為fastball、splitter調整為
change-up。
You have to look closely because they are being hidden by some change-ups, but
all these new pitches are being thrown at an angle more side-armed than his
regular release point. A more side-armed release point would impart more
horizontal movement and less vertical movement on the pitch while keeping the
speed about the same. This is exactly what we see here. So I think these
pitches are four-seamers thrown at a different arm angle.
你可以發現，那些sinkers的出手角度和一般的fastball是有些不同：出手角度較低。較低
的出手角度會造成水平位移的增加，這就是我們在圖上看到的。
When we break the pitches up this way, we see that Bannister throws at this new
arm angle early in the count, then uses the regular fastball much more later.
In fact, on two-strike pitches he is throwing his regular fastball nearly 60
percent and many of them appear to be up in the zone. This is in contrast to
last year, when he used his slider often to try to put away hitters. If this is
his new strikeout pitch, it will be interesting to see if the league adjusts.
If so, will he then readjust and go back to the slider?
我們可以發現，Bannister對決時會先用這些新品種的速球，接下來才是平常的速球。事實
上在兩好球之後一般速球的使用率高達60%，並且落在球帶的上緣。然而，去年他在兩好球
之後比較常用滑球來引誘打者。如果這項改變是他三振提升的秘密，那打者能去適應這項
改變嗎？如果可以，那Bannister的配球會回到原本的模式嗎？
Speaking of the slider: Both this year and last, Bannister has thrown a very
hard slider—again, a pitch very close to being called a cut fastball. It is
strange to see a pitcher who throws most of his fastballs in close relation to
his sliders. Because both of these pitches are close to a cutter, the
difference between Bannister's fastball and slider is much less than it is for
most pitchers.
關於滑球，從數據中我們可以發現Bannister的滑球和cutter的變化很接近，這表示他的滑
球的品質和一般的投手比起來並不太好。
It is possible that this is why Bannister wasn't having much success putting
away hitters with his slider. Even if they were fooled and guessed fastball, it
wasn't too much of an adjustment to reach the slider. With the introduction of
this new arm angle, the difference between this fastball and his slider is huge
and something else for the hitters to be thinking about.
我們可以試著做出這樣的結論：Bannister的滑球變化不夠好，因此很難用滑球解決打者。
然而，他今年調整了某些速球的出手位置，這項改變讓他的滑球看起來變化較多，因此更
容易藉由速球和變化球的差別來解決打者。