hobby horses I: the ground game

before we jump fully into the sign-and-trade season, i'd like to wrap up some unfinished 2005 business and put away the season's hobby horses. to begin with: double plays. on august 23 i looked at the cards' freakishly high turn-two rate and the tremendous run-saving value thereof. they finished the year with 196 twin-killings, the 19th-highest total in history according to mlb.com. (if you click the link, ignore the 1999 dp totals in positions 1-30, all of which are obviously erroneous.) their pace dropped off in september; they had been headed for upwards of 200 double plays and a slot in the all-time top 10.

as i noted in the original post, the cards' feat was all the more amazing because they gave up so few baserunners -- they allowed the national league's 2d-lowest obp and hence had a far below-avg numer of guys on base to double up on. leaguewide, double plays erased 9.7 percent of all runners to reach 1st base -- ie, hits (excluding doubles triples and homers), walks, and hbps. the cardinals wiped out 13.4 percent of such baserunners, or 38 percent above the norm. had they turned two at the league average rate, the cardinals would have finished the year with just 142 double plays -- 54 fewer than they actually turned. if we assume that those 54 double plays only saved half a run on average (and that's a verrrry conservative estimate, as i explained in the original post), the cards' dp premium was worth 27 runs, or about 3 wins over the course of the season. it's more likely the actual savings was 35 to 40 runs, or 4 to 5 wins in the standings.

how valuable is that? roughly the difference between jim edmonds and willy taveras, or between chris carpenter and jeff weaver.

by the way, baseball prospectus's net dp totals back up my estimate of a 54-dp premium. by BP's figures, the cardinals turned an estimated 52 double plays above the number you'd expect for a team with their number of dp opportunities.

the high dp rate leads us to a second remarkable thing about the 2005 cardinals: their off-the-charts groundball-flyball ratio. mlb has only been tracking this stat since 1999, but in that time only two teams had ever recorded gb/fb quotients higher than 1.5 (ie, 3 groundouts for every 2 flyouts) before this year: the 2002 pittsburgh pirates (1.54) and the 2003 la dodgers (1.51). st louis in 2005 recorded a gb/fb ratio of 1.72 -- nearly 2 groundouts for every flyout. the next highest ratio in 2005 belonged to the diamondbacks at 1.35. all five st louis starters ranked in the top 21 in the league in this category.

as a league, the nl registered about 1.2 groundouts for every flyout. if you multiply the cardinals' outs on balls in play by the league ratio, you get roughly 1800 groundouts to 1480 flyouts. in fact, the numbers were 2017 groundouts and 1280 flyouts -- or ~220 groundballs above the norm.

and that's how we can explain the majority of those 54 "bonus" double plays.

(disclaimer: baseball prospectus obviously calculates this stat diff'tly; all their g/f rates for individual pitchers are higher than the figures at mlb.com, and BP puts the league rate at 1.6. i don't know how BP calculates the stat; i can tell you that mlb.com excludes bunt ground outs and caught line drives from the equation. but there are probably other diff'nces as well.)

more in this vein to come.