Monday, July 23, 2007

in praise of luck

the cubs dropped two of three to the arizona diamondbacks this weekend, including the saturday game i attended, coming away three and a half games back of the division-leading milwaukee brewers and just two back and tied for second in the nl wildcard standings. because of the higher number of competitors in the wildcard race, even at a closer distance the wildcard remains probabilistically more remote in any odds generator you're likely to see, including baseball prospectus'.

it seems to me that a lot of what can be said about this club has been. i've characterized this season as best i know how -- on the balance of evidence as i see it, this is a club highly reliant on its good fortune on balls in play for the lion's share of its success. that's unfortunate to some degree as babip is a notoriously vacillatory characteristic, particularly on the pitching side -- it's been shown that the figure in any half has about a 50% chance of lying between .285 and .300, and three in four of falling between .280 and .305. the first half saw the cubs fall outside that middle range to their good fortune on both sides of the ball, and july has so far been another such event --- .312 on offense, an astounding .261 on defense -- to help the cubs to a 12-6 record in the 18 games.

how important is this babip stuff? to be sure, it's only one aspect of the game, even speaking just statistically -- there are strikeout and walk rates, flyball and groundball rates, home run and other power rates that factor into how a team performs. and these things are of course variable as well, particularly in short runs.

but it is the co-story of the year so far for this team -- firstly because it is important, secondly because the cubs are so deviant from what is to be expected.

why can we say babip and its variance is important?

these charts compare how run rates, both scored and allowed, vary respectively with babip (batting and pitching, respectively) over 12-game and 26-game runs. it does not take a math genius to see that output correlates pretty well with babip -- imperfectly of course as there are many other factors at work, but more than well enough to demonstrate that babip is important. it's particularly clear on the batting side, but no less true on the pitching side -- when balls in play fall for hits at higher rates, clubs score more runs.

the other half of the co-story of the year has been slugging -- particularly the cubs' lack of it. comparing babip variations and slugging variations over the same 12- and 26-game spans, we can see easily enough that slugging matters about as much as babip (and that slugging and babip are, of course, closely correlated themselves as slugging is mostly dependent on base hits, not home runs).

often, in fact, where runs scored/allowed jumps and babip does not, it indicates a spate of home runs better reflected in slugging percentage. this is obviously part of what is meant by saying that there are other things in the world besides babip to look at.

what can these charts tell us about the recent cubs run? the runs scored charts show the team scoring at a near-season-peak pace -- and a deep power outage as well as an elevated babip, in fact the luckiest 26-game stretch of the season for the offense. it would seem that the recent run of scoring is almost entirely dependent on a fortunate babip. on the pitching side, we see the cubs allowing as few runs as at any point this season -- but less on virtue of babip than on slugging allowed, which is near a season low over the last 26.

there are myriad conclusions one can draw from these data, but one of the most important is poorly shown here -- and it is based on the observation that the 26-game cub pitching babip chart never rises over .291. given that over any half-season of baseball a team should expect its babip against to fall over the league mean of .295 about half the time, it is remarkable that the cub staff is so far 4-for-4-months in the luck department. it's hard, i think, to overestimate the positive impact that unusual bit of good fortune has had -- after all, one can look at the 12-day measures and see that, when the club allows a babip of over .300 they also can allow the opposition an average of 5 runs per game or more.

one of the other more interesting things that could be said deals less with the team than with the expectations of its fans. none of what i'm saying today is a state secret, but the vast majority of even knowledgeable cub fans have given it short shrift anyway in their eagerness to both enjoy winning and project it into the future. coming off a homestand on which the cubs finished 7-3, acb seems to think finishing out the season at at least a .570 clip is likely, in spite of the fact that the cubs are today a .526 ballclub; cub town is talking about the swagger and effort that the manager has brought to chicago, apparently from tampa bay; at least some at goatriders are convinced that the club is just plain good. none of this is to single anyone out -- the new york times is on the bandwagon, for god's sake. and the sentiment isn't universally uncritical, as the cub reporter shows even as they draw tenuous lines between the cubs and past world series champions.

but it is amazing to realize that the lowest low of the year -- the game 53 "turning point" which included lou piniella's now-legendary rant the day after the zambrano-barrett dustup -- represented the approximate midpoint of the single stretch in this season during which the cubs had played at anything like luckless, fortune neither particularly favoring nor disfavoring them with respect to balls in play, offensive (.298 babip, 4.29 rs/g) and defensive (.287 babip, 4.48 ra/g). the club went 19-23 in that stretch.

it's a sobering thought for me -- even as i love the hell out of this winning run, even as i take my family to the park to yell them on, even as i line up september tickets just in case -- that this ballclub's luck should by all rights have run out long ago. there's no swagger here, no managerial prowess, no turning point, no issue of effort, and certainly (short of dementia) no reason to expect much in the way of continuation. there's simply a club that started to get really lucky at a really good time, in fact has been pretty damned lucky all year.

thank god for luck -- no team can win without some. i'm left to ponder that the cubs are drawing very heavily on their account with dame fortune -- but isn't this club, of all clubs, entitled to?

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