Derek Jeter and Alex Rodriguez in the Playoffs

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http://www.beyondtheboxscore.com/2009/6/16/910719/testing-conventional-wisdom-derek


Derek Jeter - the Captain, the True YankeeTM  He took his first 12 teams in
New York to the playoffs, winning the world series 4 times.  A .309 playoff
batting average and a .302 World Series average among other memorable playoff
exploits earned him the name Mr. November.

On the other hand, we have Alex Rodriguez.  A-Roid.  A-Fraud.  Reports say
he's one of the worst teammates around, and steroid rumors will linger
throughout his career.  To top it all off, his playoff performance has earned
him the nickname Mr. May.

Playoff performance certainly tends to suffer from the dreaded uncertainties
of small sample sizes.  As such, it would be prudent to study the playoff
production of these two polarizing figures in recent New York Yankees
history.  The first question that comes up, as an objective observer, is that
of how to analyze the production.  In order to both preserve some rigor while
maintaining some ease in the method, I decided to use playoff OBP as the
measuring stick.  Much of my method is adapted from the appendix of The Book,
and is based mostly on the concept of regressing towards the mean to find
true OBP skill.


For the Captain, we have 25 different postseason series from 1996-2007.  Over
these 11 years, Jeter posted an OBP of .390 in 17145 PAs, and so we can
assume his OBP skill to be .390 due to the large sample size.  However,
Jeter's postseason OBP in this span is a mere .374 in a significant sample of
546 plate appearances (a number that is remarkable in itself).  This is
because we haven't adjusted for the quality of pitching of playoff teams.
 Over the 1996-2007 period under observation here, AL playoff teams allowed
an opposing OBP of .307, a very impressive number in the period including the
high offensive period of the late 90s/early 2000s.  Now, with this we can
calculate Jeter's expected OBP: Expected = (Offense + Defense - Average).
 With the league OBP roughly equal to .340 over this period, we expect
Jeter's OBP to be .356.  Jeter's .374 OBP beats this expectation by 18
points.  Over 576 plate appearances, this is just under 1 standard deviation
from the mean.   Among players with an expected OBP of .356, only 20% of
players would be expected to perform better.  So it does appear that yes,
Derek Jeter may possess some sort of tangible ability to perform above his
true talent level in October.

Can we say the same about A-Rod during his time in pinstripes?
 Unfortunately, we only have 108 playoff plate appearances, which leads to
much more variance, but we can still examine what we have.  In the harder
offensive times of 2004-2007, the average OBP dropped to .336, and we also
see the OBP allowed by playoff teams drop to .304.  Rodriguez put up a
mammoth OBP of .404 in that 4 year span.  Regression over his 3532 plate
appearances leaves us with an estimate of .395 for Rodriguez's OBP skill.
 Calculating his expected OBP in the playoffs as above results in an expected
OBP of .363.  It appears conventional wisdom may be on the right track here,
as A-Rod's OBP over his 108 playoff PAs is only .343.  However, since the
sample size is so much smaller, this is only .45 standard deviations from the
mean.  This result is much less significant than that with Jeter.  Still, we
would expect 63% of players with a .363 OBP estimate to perform better than
A-Rod's .343.  Perhaps the established reputation is correct in saying that
Rodriguez performs worse in the playoff months.

It's important to stress here in this analysis that we are comparing Jeter's
"clutchiness" to players with similar skills to Jeter, and we are comparing
A-Rod's "clutchiness" to players with similar skills to A-Rod.  Not only does
this mean that Rodriguez was still above average in the playoffs (whereas
Jeter was, as advertised, great), it means that managers, fans, and the media
shouldn't be clamoring to be rid of A-Rod or asking for a replacement with a
lower skill level.  Finally, we are still subject to small sample sizes.
 Certainly, the 3500 plate appearances from the regular season tell us more
about what to expect in the postseason than the 100 postseason appearances,
and similarly, 17000 PAs tell us more than 500.  This analysis shows how
these players have performed in the past.  If somebody held a gun to my head
and forced me to predict a stat line for their next playoff series (whenever
that may be), I would certainly err on the side of the larger sample size.

--
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◆ From: 140.112.5.3
推 DaLanPa5566:純看標題:隊長跟神確定進入季後賽...............
→ DaLanPa5566:吉拉迪:那你們兩個好好加油,兩個人要守九個人的位置喔
→ DaLanPa5566:而且要一邊打擊一邊盜壘!!!啾咪
推 kimifort:只看第一句 基特船長首次帶12隊進入季後賽還贏了4個WSC
推 DaLanPa5566:樓上那個好威,一個人帶領12隊一起進入季後賽
→ FlyFreedom:...................................................
推 nicefu:又不是NBA(已結束)...季後賽勒
推 hagridsu:一樓的ID好酷
推 Moscom:還沒看就猜大概在酸arod
推 fenghoho:季後賽XDDD
→ sivid:樓上上猜錯
推 sherlockt:整篇大意是A-Rod在季後賽的表現沒有表面上看起來那麼差
→ sherlockt:但是季後比Jeter弱是事實 巨星光環讓他更容易被嘴砲
推 a78544521:我笑了XD
推 kimifort:用google快速翻譯 好像還有提到Arod其實季後賽有打比較好
→ kimifort:因為很多球隊進入季後賽OBP都有下降 但Arod卻反升高
→ kimifort:儘管跟Peter比起來還是遜色很多
推 BlueStyle:怎又冒出一個Peter
→ sherlockt:不過AVG對球迷來說吸引力還是比較大吧 大家喜歡H =///=
→ characterlu:Peter?
推 stevely:hagr大 你害我去看一樓的ID了 XDDDDDDDDDDDD
推 DaLanPa5566:誰叫我??