The Strasburg Shutdown and What We Don’t Know
http://ppt.cc/_B~n
by Dave Cameron - September 10, 2012
On Friday night, Stephen Strasburg took the mound in Nationals Park for the
last time in 2012. Since I live about six hours from DC and I hadn’t seen
him pitch in person yet, I figured I shouldn’t pass up on the opportunity to
see him for myself, so I made the drive up on Friday afternoon. As you’ve
undoubtedly heard, Strasburg wasn’t particularly sharp on Friday, getting
removed after throwing just three innings, and so the Nationals decided that
Friday was his final start of the year, moving his shutdown up one start and
ending his season at 159 1/3 innings.
星期五是Strasburg在2012年的最後一次登板 這場比賽Strasburg不像之前那樣主宰
投滿三局就被球隊換下場 今年他投了159又1/3局
It’s obviously a rather controversial decision, and I’ve advocated for the
position of more aggressive usage, skipping starts and manipulating the off
days to try and make him available for the postseason. Watching him struggle
in his final start didn’t disuade me from believing in the merits of that
kind of approach, and I do think that perhaps there were alternative ways of
handling his workload that might have allowed him for pitch deeper into the
season. However, the unavoidable reality of this situation is that everyone
is dealing with a great quantity of unknown variables, and for any of us to
say that one decision is distinctly better or worse than another is probably
an on overestimation of our own knowledge.
這當然是最爭論不休的決定
而我(作者)主張更積極的使用方式: 直接跳過關機 然後讓他持續投到季後賽
最後一場的掙扎並無法讓我去相信值得如此這樣做
而且我相信是有其他的方法來監測他的投球負擔 這樣可以讓他在球季中投的更長
然而事實上不可避免的事實是 有大多大多的變數了
說一個選項是比較好或是壞 很可能是高估了我們的智慧與知識
The secret to keeping pitchers healthy is still perhaps the biggest unknown
entity in baseball, and our ability to predict which pitchers are going to
stay healthy is not much better than simple dart-throwing. As more focus has
shifted to the causes of physical breakdown, workload has gotten more than
its fair share of attention, and efforts to avoid overuse have become far
more commonplace in the last 10 to 15 years. However, even with this focus on
responsible workloads, we haven’t seen a sea change in how often pitchers
are getting hurt.
如何去保持投手的健康至今仍是最大的謎團
我們去預測投手保持健康的能力 事實上並不比射飛鏢來的好
近10-15年都在注意避免過度使用投手 但就實際情況 我們並沒有發現投手更不容易受傷
Given that pitchers have different physical strengths and weaknesses, it’s
likely that a one-size-fits-all approach isn’t all that useful, and what
might be good for one pitcher could be bad for another. So, while we can say
with some certainty that Strasburg would have been at a higher risk of injury
if he would have thrown 250 innings this year rather than the 160 he actually
threw, we don’t really know where he lies on the reasonable usage spectrum.
You could probably make a case for any number between 160 and 250 and have a
reasonable amount of evidence on your side that the total innings count wouldn
’t be significantly more harmful than any other number in that spectrum.
And, with a knowledge gap that large, it’s just hard to have any kind of
strong opinion about what the right number for Strasburg this season actually
was.
每個投手的身體強度與弱點都不一樣 使用同一標準並不是很有用的
當我們說 假設Strasburg今年投250局會比投160局來的更有受傷風險 其實我們不知道
也許可以去蒐集160-250局的投手數據
然後有個合理的證據來證明投更多的局數 其實不是真正影響投手受傷的原因
接著 160-250的局數範圍也過大 你也很難去找到這季正確關機Strasburg的局數
The Nationals obviously erred on the side of caution, giving their ace a
number pretty close to the lower bound, and refusing to shift his starts
around to maximize the leverage of those innings. They wanted to allow him to
maintain his regular patterns, and again, this is an area where we simply don
’t know the effects of alternative options. There just isn’t much
historical precedence for this kind of situation, and the uniqueness of each
pitcher’s body limits what we could learn from earlier cases anyway.
國民隊明顯的對於Strasburg非常小心 在低限度下就讓他關機 而且不讓他再投更多局數
國民想讓Strasburg保持平常的狀況 但這又是一個領域 我們基本上不知道這樣做有何效果
我們並沒有太多的歷史資料可以來分析 而
且每位投手的體能都是獨一的 這限制了我們的研究
So, the Nationals chose something like the most conservative usage path
possible, but given how little is known about keeping pitchers healthy, their
decision is certainly within the bounds of what one could consider
reasonable. And, of course, health isn’t the only variable in play here.
所以在我們對保持投手健康極小的知識下 國民隊做了最保守的方法
As we saw on Friday night, there is some evidence that Strasburg is currently
somewhat less effective than he was earlier in the season, and perhaps a full
season of pitching is starting to catch up with him to some degree. For
instance, take a look at his PITCHF/x velocity chart:
當我們看星期五的比賽中 有些跡象顯示Strasburg的表現比季初來的差
我們來看看PITCHF/x的球速表
http://www.fangraphs.com/blogs/wp-content/uploads/2012/09/Strasburg.png
While he has mostly maintained his average velocity throughout the summer,
his peak velocity is down from earlier in the season. In May and early June,
he was regularly getting up into the 98-99 range, but lately, he’s topped
out at 96 or 97. It’s not a smoking gun, but given that velocity tends to
increase as the season goes on, the fact that Strasburg’s fastest pitches
have gotten a little bit slower suggest that there is some legitimacy to the
idea that he’s beginning to wear down.
雖然Strasburg幾乎維持了他的火球球速 但他的極速比之前下降一些
在5月以及6月初 球速是98-99 之後則是96-97
這似乎有個合理的解釋: Strasburg開始累了
There’s also some evidence of declining dominance in opposing batters
swinging strike rates. In his first start of the season through July 15th —
his first 18 outings — opposing batters only posted a swinging strike rate
below 9% twice, and they were over 13% seven times. In his last 10 starts,
however, he only posted a swinging strike rate over 9% five times, and only
once got over 13%. His command also wasn’t as crisp as it was earlier in the
year, as he walked three or more batters in a game four times in his last 10
starts after doing it four times in his first 18 starts.
另一個現象是Strasburg沒有像之前那樣的宰制對手
在7/15前 前18位出局數中的揮棒落空率 有兩次低於9% 有7次則是高達13%
在最近的10場先發 揮棒落空率有5次高過9% 但只有一次超過13%
另外他的控球也沒有像之前那麼精準 最近10場有4場投出3次以上的BB
前18場中 只有4次
Early season Strasburg was the most dominant pitcher in baseball, at least on
a per-innings basis. Recent Strasburg has been more human, mixing in some
good starts with some clunkers. If this trend was going to continue, it’s
certainly possible that the gap between Strasburg and Ross Detwiler in
October wouldn’t be so large that swapping them would result in a huge
change in expected outcomes. In fact, you could argue that the outcome
differences now aren’t even that large.
季初Strasburg是主宰比賽的投手 但現在他比較像人類(幾場投很好 幾場掙扎)
如果他持續這種表現 那Strasburg跟Detwiler的差距就沒有之前那麼大
Strasburg’s posted a 2.82 xFIP this year, just about 1.50 runs per nine
innings better than Detwiler this season. Strasburg’s posted higher than
average BABIP and HR/FB rates, while Detwiler has been below average at both,
so you might want to adjust that gap down slightly to account for the fact
that there might be some difference in skills in those FDP areas. So, maybe
the gap is 1.25 runs per nine innings instead. That’s certainly a big
difference, but we also have to remember that October baseball is not the
same as regular season baseball, and that managers can be much more
aggressive in their bullpen usage in the playoffs. Given how deep Washington’
s relief corps is, it’s unlikely that either pitcher would be asked to go
beyond six innings, and five is probably more likely against a good offensive
opponent. So, instead of 1.25 runs, we’re probably dealing with something
closer to 0.7 runs per start difference.
Strasburg這季的xFIP是2.82 大概每九局比Detwiler多守住1.5分
他的BABIP跟HR/FB高於平均 而Detwiler則是低於平均 調整以後兩者差距大概是1.25分
事實上差距還是相當大 但請記得季後賽跟普通球季不同 教練通常會更加使用牛棚
以國民隊的牛棚深度 大概很難會讓先發投超過6局
以每九局多失1.25分來看 最後很可能是多失0.7分
And that’s using Strasburg’s full season line. If you think he’s wearing
down, maybe he’s more of a 3.25 xFIP guy going forward, and that would push
the difference more towards 0.5 runs per start. Don’t be fooled by those “
ERA since the All-Star break” graphics that say that there’s no drop-off
here, but a half run gap isn’t overwhelming, especially if you think that
the trade-off is getting a healthier Strasburg for the future.
如果使用Strasburg整季 外加目前持續疲累的程度 xFIP可能是3.25 大概是每場多丟0.5分
別被明星賽前後的ERA變化圖表給騙了
And then, of course, there’s the significant variance around player
performance in small samples to begin with, and we’re not just talking
Strasburg and Detwiler here. There’s a real chance that the playoff games
that Strasburg would have pitched in wouldn’t have been close enough to be
decided by the quality of the starting pitcher anyway. If we built a
histogram of the potential outcomes of any Strasburg playoff start, there
would be a tail on one end that represented a blowout by the Nationals, in
which they could probably roll out any pitcher they wanted and still win the
game. Likewise, there would be a tail on the opposite side of the spectrum
that represented a dominating performance from the opposing starter so that
even a great performance by Strasburg would still result in a loss.
[這整段其實是廢話 作者說季後賽樣本小 變化很大 小史可能會投不好
交給其他投手說不定更會贏 然後如果小史投的好也不一定會贏 因為對方投更好...]
The starting pitcher is an important factor in the end result of a ballgame,
but it isn’t the deciding factor, and it’s certainly possible that the
decision to use Detwiler instead of Strasburg ends up not having much of an
effect on the Nationals playoff chase at all, simply due to outcomes that
have nothing to do with the quality of each pitcher. Combine that with the
volatility of projecting Strasburg going forward, the huge unknown that is
pitcher injuries and reasonable workloads, and the fact that the Nationals do
have a good team even when Strasburg’s not on the mound, this decision by
the Nationals is certainly defendable.
雖說先發對比賽影響很大 但不是決定性因素
就算小史停機也對國民隊進軍季後賽的影響不大
結合預測小史的外來表現,未知的受傷風險及合理的工作量 將小史停機是相當合理的
況且國民沒小史也是好球隊
It’s not the only defendable decision that they could have made, but this is
an area where it just doesn’t make much sense to take a strong stance one
way or another. There are so many unknowns that the best thing we can do is
admit that we don’t know enough to have a strong opinion either way. The
Nationals are doing what they think is in their franchises best interests,
and they very well may be right. They may also be missing a chance to take a
deep playoff run, and the reward that comes from that kind of run might be
worth the extra risk. There are a lot of maybes here. When there are this
many questions that we just don’t have the answers to, the best thing we can
do is acknowledge where our limits are. On handling Stephen Strasburg, we
just don’t know enough to say whether any one decision is better than
another. The Nationals made a decision and stuck with it. That’s probably
all they could have done.
有太多未知的事情導致我們無法做出最好的選擇
國民也只是做出他們認為對球團最大的利益選擇 而且他們很可能是對的
他們或許會錯失一些打入WS機會 這有可能超出所估計的額外風險
但是有太多的如果與假設了
我們能做的最好的事情就是知道我們的限制在哪
在Strasburg的例子中 我們無法說哪些是更好的決定
至少國民隊做出了最終決定而且執行它