What Happened Cole Hamels?

You wouldn’t know it if you were just focusing on his 3.42 ERA and 1.08 WHIP, but this has easily been Cole Hamels‘ worst season as a Major Leaguer. His SIERA, xFIP, and FIP have all jumped above 4.00 for the first time, while both his xFIP- and FIP- have surged into the triple digits for the first time (higher is worse). Hamels missed two months of action thanks to an oblique strain, but since it was a non-arm injury, we certainly couldn’t blame it for the collapse of his underlying skills. What’s going on here?

Let’s start by looking into how he has managed a mid-3.00 ERA despite a SIERA mark approaching 5.00. With a weak 15.4% strikeout rate and 8.7% K%-BB%, Hamels has seen his strikeout rate plummet, but good results have continued. It’s actually pretty easy to spot the explanation — it’s all in the BABIP. His HR/FB rate and LOB% are both a bit better than the league average, but his .230 BABIP is far below the .297 mark posted by American League starting pitchers. Since no one likes to accept the blind “great fortune” explanation, let’s see if there’s any semblance of data that would justify a depressed BABIP.

To start, his line drive rate sits at just 17.5%, which is well below the 20.7% AL average. Like most pitchers, his line drive suppression skills haven’t been entirely consistent throughout his career, but what’s done is done this season, and a low LD% has certainly helped suppress his BABIP.

Next, let’s move onto the rest of his batted ball profile, heavy on grounders, and light on pop-ups induced. That’s not a good recipe for a low BABIP as grounders go for hits far more often than fly balls and he isn’t benefiting from the easy outs that come from pop-ups very frequently. Overall, his batted ball distribution suggest something around the league average with one batted ball type being a positive, while two others are a negative.

But what about inducing weak contact you ask? Even though all studies have shown a weak link between Soft% and Hard% and BABIP, we’ll take a look at those marks anyway. His Soft% is actually well below the league average, while his Hard% is well above it. Well that definitely doesn’t help his BABIP cause! While the correlation between those and BABIP isn’t strong, it’s not nothing. And obviously, a pitcher would prefer to generate soft contact versus hard.

Heading into the season, Hamels’ career BABIP stood at .287, so he did show some slight BABIP suppression skills previously. However, he posted marks of at least .290 every season since 2012, so all of those lower BABIP seasons came before that. What about the Rangers defense? The team has been almost exactly average, ranking 16th in MLB in UZR/150, while the only infielder that has posted a positive UZR/150 has been Adrian Beltre.

So, it would appear that Hamels has been suppressing hits on balls in play with the help of smoke and mirrors. If his skills don’t improve in a hurry, that BABIP is going to rise and bring his ERA along with it. And what about those skills?

His career low strikeout rate has been driven by a SwStk% that has fallen below 11% for the first time. Amazingly, every single season he has played, Hamels has posted a double digit SwStk%! This is the first year it has slipped below 10% and the league average. Hitters are swinging less often at his pitches outside the zone and the most often of his career at pitches inside the zone. On the whole, hitters are swinging less than ever before, while making significantly more contact on the outside the zone pitches they are swinging at. His strike percentage has also declined to a career low, probably because batters aren’t swinging as often at balls off the plate.

His fastball velocity is down, but not dramatically so and certainly not enough to ring alarm bells and cause such a precipitous drop in strikeout rate. His pitch mix is essentially the same as always, but once we dive into his pitch type splits, we immediately notice the problem, or should I say, problems. Every single one of his pitches is generating a SwStk% mark worse than last year. In fact, you would have to go all the way back to 2013 before finding a pitch that induced a worse SwStk% than the same pitch this year. And while his signature changeup still remains excellent with an 18.2% SwStk%, that’s still a far cry from what we’re used to — he’s been in the low-to-upper 20% range every single season of his career and sports a career mark of 25.8%.

I don’t know what’s going on here to cause all his pitches to become so much less effective, but either his ERA is due for a major spike or his skills rebound swiftly. Since he has already thrown over 100 innings with these drastically reduced skills, I would bet on the former. With a still solid ERA and a respected name, you could likely still get a nice return if your leaguemate doesn’t bother to look under the hood.