I've seen some managers bat their pitchers 8th. Tony LaRussa was one of the more noticeable ones. Is this move statistically sound? Why or why not?
Ignore cases like Dontrelle Willis early in his career or Michah Owings, both of whom are good hitters anyway. I'm talking about run-of-the-mill, bad at hitting, pitchers.
La Russa's penchant for batting the pitcher 8th got a fair amount of press a few years ago.
This link from Retrosheet does some significantly more detailed statistical analysis about general lineup composition.
Here's a PDF from 1999 that does a comparison between Larussa and Gant.
These basically conclude that there is essentially no statistical difference.
And finally, here is the Sabermetric Guide to Managing. It includes an optimized lineup and clearly claims that batting the pitcher 8th is better.
If two people strike out, or get out in any other fashion, and 3 people get onto base, your 6th and 7th hitters have a chance to bring in runs by getting a hit. Thus pushing the pitcher back to 8th to allow for this extreme scenario of giving your self two chance to get a run score after immediately getting two outs at the start of your lineup.
get-out get-out on-base on-base on-base hit=run hit=run pitcher last man
Several reasons, basically along the lines of "you don't want the pitcher batting last in the 9th inning":
In the case of a no-hitter, everyone will have batted 3 times and the pitcher will be last at the plate. This is a really bad situation; if it's been a pitcher's duel all night and the score is only 1-0, your pitcher, typically your worst batter, is your last hope.
A team, statistically, gets an average of 9.27 hits in a game. So, on average, you can expect everyone to bat four times, and again, your pitcher will be last at the plate in an average situation.
Basically, you don't want to put him anywhere else. Read up on Wikipedia, but essentially, #1 should be the best baserunner (including stolen base percentage) and have a good OBP made up primarily of hits. #2 should be able to get on base by any means necessary, and failing that should be able to make the sacrifice to advance a runner. #3 should be good at RBIs and second-best OBP. These guys' job is to "warm it up" for the cleanup hitter, #4; this should typically be your slugger, the best batting average with runners in scoring position, highest home run count, the works. #5 and #6 are your best RBI men (to bring home the "heart of the order" when they get on base); their OBP is typically driven by home runs and sacrifice hits. 7 and 8 are where you stick the weaker players, with 8 being the traditional slot for the worst fielder. The 9th slot varies; in the AL, where the pitcher doesn't bat, this spot's typically filled by the guy you'd use as your #1 if you didn't have the guy you put in #1; he's a "second leadoff hitter" designed to get a good baserunner on base for the top of the order. In the NL, #9 is traditionally the pitcher's slot, though if your team is hitting well, you can arrange your lineup similarly to the AL and put a "second leadoff" into the #9 slot.
I think that they want to do this so even if he is the last out,then the number 9 hitter will be able to get on base ,and then he will have the top of the lineup to hit him home. Usually your #9 guy will be really fast. The only disadvantage is that if it is an important at bat, you may have to pinch hit your pitchers earlier than you want to.
