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round and round she goes . . . . .

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just in time for the latest news about the cards' april rotation: a statty look at something called "starting-pitcher leverage" over at the Hardball Times. what's SP leverage?

Local lore here in Chicago proclaims that [White Sox manager] Al Lopez used staff ace Billy Pierce as often as he could against the best opposing teams---the Yankees and Indians---to give the White Sox a little additional chance. Baseball's memory also tells us that Casey Stengel did the same with Whitey Ford,
everybody get it? rather than waste your best pitcher on weak teams that a lesser hurler can beat, you match him up as often as possible against the toughest opponents; squeeze more marginal wins out of him that way.

according to derrick goold's sunday post at Bird Land about the rotation, tony and dave are practicing a form of leveraging. "The rotation is set as much for who pitches against what team as who doesn't pitch against certain teams or in certain ballparks," goold notes; this remark from La Tony reinforces the point:

"What we've always done (is) you take it out for six weeks and you create what you feel like you could do with starting pitching for every series we play and have a chance to win the series," La Russa said. "The way off days and the matchups fall, we feel this is our best shot."
the Hardball Times piece includes a simple formula for measuring leverage; i thought i'd apply it to the cardinals' early-season rotation to see whom tony and dave are leveraging. to get that little exercise in motion, here are the opponents each starting pitcher will face in his first 6 starts (about 1/5 of the season):
carpenter mets astros pirates pirates cubs cubs
wells mets pirates brewers cubs reds brewers
looper mets pirates pirates cubs cubs brewers
wainwright astros brewers giants reds cubs astros
reyes astros brewers giants reds brewers astros

THT's formula is a simple one: you simply take the average of a given pitcher's opponent teams' winning percentages, and divide that by the winning percentage of all opponents on the team's schedule. let's carpenter as an example, applying 2006 winning percentages just to keep it simple. his 6 opponents had 2006 winning percentages of .599, .506, .414, .414, .407, and .407 --- an average of .458. now divide that by the winning percentage of all st louis opponents --- the cards' first 30 opponents had an average 2006 winning percentage of just .468 --- and you get a quotient of .98. so carp's first six opponents are 2 percent less difficult than the average cardinal opponent during that stretch.

as measured by 2006 winning percentages.

but obviously, this isn't 2006; we just used those figures as an example. to make this slightly more meaningful, let's apply some reasonable projections of 2007 winning percentages and see which pitchers are being leveraged by that standard. i'll go ahead and use the w-l percentages posted in RLYW's Diamond Mind projection blowout last week; i trust those numbers as much as i trust any. here are RLYW's projections for the cards' first 30 opponents:

opp games est
wpct
mets 3 .525
cubs 6 .519
brewers 6 .500
astros 5 .494
giants 2 .488
pirates 5 .457
reds 3 .451

over the 30 games, that averages out to a .492 winning percentage. now let's look again at which pitchers are facing which teams, and apply the THT leverage formula:

1 2 3 4 5 6 avg lev
carpenter mets astros pirates pirates cubs cubs .495 101
wells mets pirates brewers cubs reds brewers .492 100
looper mets pirates pirates cubs cubs brewers .496 101
wainwright astros brewers giants reds cubs astros .491 100
reyes astros brewers giants reds brewers astros .487 99

well, wasn't that a worthwhile exercise. . . . . . i'm so glad i went to the trouble. lest the whole thing (and this whole post) be a complete waste of time, let's make a logical adjustment here. leverage can be measured by things other than raw winning percentage. in this case, while the mets have the best projected winning percentage on the st louis schedule, they are definitely not the team the cardinals want the most leverage against --- because they play outside the division. the top nl central rivals --- cubs, astros, and brewers --- are the teams st louis wants the most leverage against. (i'll grant that the cards and mets might end up vying for the wild card --- but the same could be said of all the in-division foes, so that's a wash.) to reflect the greater significance of the games vs the cubs astros and brewers, let's assign a premium --- wild-ass guessing, i'm going to make it .050 of winning percentage --- and recalculate. here's the table, one last time:

1 2 3 4 5 6 avg lev
carpenter mets astros pirates pirates cubs cubs .520 100
wells mets pirates brewers cubs reds brewers .517 99
looper mets pirates pirates cubs cubs brewers .521 100
wainwright astros brewers giants reds cubs astros .524 101
reyes astros brewers giants reds brewers astros .521 100

dammit . . . . . all that pencil-scratching for nuthin'. that's not to say that tony n dave aren't seeking to exert leverage; they're simply applying different levers from the one described here. e.g., "the astros can't hit a curveball, so let's start wainwright vs them twice," or "wells has a 3.06 career era vs the cubs," that sort of thing . . . . . i prob'y should have spent my time looking into those. have at it in the comments thread, if'n you're interested.

i guess the most significant thing about the way the rotation has been set up is this: chris carpenter will get an extra day's rest 5 times in his first 10 starts. as we discovered during the postseason last year, carpenter thrives on extra rest. his era on extra rest last year (in 7 starts, including world series game 3) was 0.82; his whip was 0.585. he was completely unhittable on 5+ days' rest.

the other great thing about the rotation: it only has to cycle through one more time before the real games begin. st louis plays the marlins today; gameday link here.