it snuck up on me a little, but it's pretty clear that carlos beltran is getting dramatically worse results in july, august, and september than he did in april, may, and june.
so much so, that a player whose outcomes sustained an outstanding offense for months has become a drag on the team.
the difference is stark. in april, may, and june, carlos hit for a 137, 195, and 145 wRC+. in july, august, and very early september, he hit for a 65, 79, and 27 wRC+.
now, it's not self-evident that these bad results must be the result of some external cause. his BABIPs in the first three months were .294, .313, and .354 -- pretty good, and certainly in the last case a little lucky. in the last two and a half months, his BABIPs have been .203, .250, and .158, which are pretty putrid.
even over two months-plus, hideous batted ball luck is not an improbable explanation. remember, you're talking about a 66 balls in play in july, 80 in august, and 20 in september. the difference between a .300 BABIP and a .200 BABIP over those 166 BIP is 17 hits in two and a half months.
the first sign i saw indicated that something more than an incredibly poor string of batted ball outcomes might be at issue was the shocking decline in his walk rate. over april, may, and june, beltran's walk rate was 15.4%, 11.4%, and 10.4% -- all excellent walk rates. in july, august, and september, his walk rate was 4.4%, 7.6%, and 6.9%. that's a pretty shocking drop-off from outstanding plate discipline to pretty weak plate discipline.
since walk rate stabilizes in about 200 PAs, we should expect that the sudden, dramatic change in his walk rate is meaningful. he had more than 300 PAs in april, may, and june, and more than 200 in july, august, and september.
maybe the most dramatic change in beltran's approach is documented after the jump.
as his walk statistics indicate, beltran's discipline has disintegrated. his swing statistics illustrate this problem dramatically. perhaps more importantly, his contact skills were excellent. though the plate discipline stats don't tell a completely stark picture, there's significantly more swinging late in the season, and diminished contact.
april: 25.3% o-swing, 62.8% z-swing, 40.2% tot swing -- 66.1% o-contact, 89.0% z-contact, 80.3% tot contact
may: 32.2%, 75.0%, 50.4% -- 60.3, 88.9, 78.4%
june: 30.8%, 71.2, 48.3% -- 77.3, 87.1, 83.5%
july: 33.3, 65.9, 46.4% -- 55.6%, 91.6%, 76.0%
august: 32.1, 78.6, 51.3 -- 58.2, 90.4, 78.6%
september: 43.5, 69.7, 54.4 -- 50.0, 91.3, 72.1%
league average: 30.7%, 64.6%, 45.9% -- 67.0%, 87.3%, 79.8%
o-swing means his rate of swinging at pitches out of the zone; z-swing means his swing rate at pitches in the zone. similarly, o-contact means his contact rate when he swings at pitches out of the zone; z-contact means his contact rate when he swings at pitches in the zone.
in short, for two of three months in the first half, he swung at an average number of out of zone pitches or better. in the second half, he has swung at balls out of the zone at a significantly higher than average rate; what's more he's far, far below league average at making contact with those pitches.
he swings pretty freely at pitches in the zone (except in april) throughout the season, and he still has the ability to make contact with the pitches in the zone. still, his overall contact rate is below average in the second half, and mostly above average in the first half (with a slight dip in may).
the quality of his contact doesn't seem to have diminished terribly. his monthly ISO statistics don't look outrageously out of kilter. starting in april, his monthly ISOs are .205, .380, .208, .250, .188, and .158. his may ISO looks like an outlier, and his september number is not remarkable, given that we're less than two weeks into the month. with those two exceptions, beltran's ISO has hovered in the .200+ area both early and late.
his line drive rate -- to the extent we can rely on it in monthly samples -- doesn't look bad in the second half either. starting in april, his monthly LD rates are 14.3%, 18.9%, 22.1%, 23.5%, 21.3%, and 20.0%. by line drive rate, his second half looks just as solid as the first half.
it's also worth noting that he enjoyed some outstanding home run rates early on, which have lagged since then. starting in april, he had 21.7%, 33.3%, 15.2%, 16.7%, 12.9%, and 16.7% HR/FB ratios. he has a 15.8% career HR/FB rate. the may HR rate could explain his outlying ISO numbers, as well as some of his weaker discipline numbers that month; if one of every three balls you hit in the air was leaving the park, you'd swing a lot too.
what we don't know much about is the status of his health. we know he had some sort of finger tendon injury, and i believe his knees are bothering him a fair amount. his injuries certainly aren't making him swing at more junk outside the strike zone, though they may be driving down his contact rates, especially if his knees are keeping him from getting full extension on balls off the outside edge of the plate.
it looks to me like there are a constellation of issues driving down his late season numbers. his early season numbers - especially his home run rates - were probably unsustainable to begin with. he's clearly striking out more and walking a lot less for reasons that are neither bad luck nor direct effects of his injuries. you could argue that his diminished discipline may be an effect of pressing at the plate, which may in turn be a response to bad outcomes or an effort to overcompensate for his injuries. surprisingly, there's very little evidence that he's actually producing weaker contact when he does make contact, and he is continuing to make very good contact in the zone -- which suggests at least some of the bad outcomes are also luck-related.
if i were mike matheny, i'd have a very frank conversation with him about his health. assuming he didn't identify significant concerns about his injuries, i'd sit down with him and mark mcgwire to talk about his approach at the plate. i'd tell him he doesn't need to swing more to compensate for his numbers; instead, to take good approaches each time he's at the plate and trust that he'll make contact with the good pitches. his numbers should even out if he lets them. right now, he seems to be getting in his own way.