José Iglesias Swings Too Much. Or Too Little. It’s Complicated.

There’s no one way to hit well, but there is one constant in hitting: batters swing too often. The intuition behind that fact isn’t hard to get to: if you swing at a pitch outside the zone, you’re taking a ball and turning it into weak contact (it’s hard to hit pitches outside the zone with authority) or a strike — that’s bad! If you swing at a pitch in the zone, you’re turning a strike into either a strike (if you miss) or contact. Swinging is so bad outside of the zone that it overwhelms the advantages of hacking in it.

I don’t mean to imply that this should extend to logical extremes — you can’t literally never swing — but the numbers are clear. In 2020, batters were worth 3,030 runs below average when swinging. They added the same amount when they didn’t swing. This isn’t a fluke: batters have already added 1,350 runs relative to average by taking pitches this year — you guessed it, they’ve cost themselves as much by swinging. In every full season since the advent of pitch tracking in 2008, swings have cost offenses at least 6,000 runs. It’s just a fact — hitters swing too frequently.

José Iglesias has probably never heard this advice. He’s in the midst of one of the swing-happiest seasons of recent memory, and he’s doing it in exactly the way that worries you — a mountain of chases. There’s just one twist — it hasn’t sunk him just yet, despite everything I said up above, and it’s fascinating seeing him survive.

The top of the chase rate leaderboard is filled with powerful hitters. Salvador Perez leads the way so far, with a 49.1% swing rate on pitches outside the zone. Luis Robert is in second. Javier Báez is in the top 10, as is Nick Castellanos. I don’t mean to say that you can’t be a good hitter when you get fooled that often — all of the batters I named are having good years. They’re producing in a particular way, though: plenty of misses, but loud contact when they do connect.

Let’s play a classic Sesame Street game. One of these things is not like the other:

Iglesias is definitely not doing damage when he connects. He’s also not missing. What gives?

As it turns out, his spot on this list is justified. It’s hard to notice, though, because Iglesias plays a throwback game, heavy on contact and light on takes of any type. He’s simply kicked it into overdrive this year, and something has to give — either his production or his swing rate.

Iglesias the free swinger is not a 2021 development. He’s never drawn walks at a robust rate, and starting in 2018, he leaned into it: he’d been swinging too infrequently at pitches in the zone, and started to amp up his swing rates across the board to make up for it:

Pay particular attention to his zone swing rates. The combination of those low numbers — he’s never swung at even an average number of in-zone pitches — with his slap-hitting profile made pitchers’ jobs easy. Pour strikes in, watch Iglesias take, and profit. He’s faced an above-average number of pitches in the strike zone every year of his career.

Another thing you need to know about Iglesias: he’s a tremendous contact hitter. In his career, he’s made contact with 80% of the out-of-zone pitches he swings at. That’s higher than the league’s contact rate on all pitches, balls and strikes combined. Chasing hurts less when you almost never miss.

Through this lens, the whole gambit makes more sense. Most batters should swing less, as we already covered. When you’re a patient swinger with a poor batting eye, though — and make no mistake, Iglesias has swung at too few strikes and too many balls in every season of his career — things might not be so straightforward.

We’ve already covered how bad swinging at pitches outside the strike zone is, but let’s put numbers to it. So far this year, batters have taken 68.3% of the out-of-zone pitches they’ve seen. That’s been worth 2,596.4 runs to them, or roughly six per 100 takes. They’ve swung through another 12% — worth -913 runs, or -12 runs per 100 pitches. Finally, they’ve made contact with another 14.7%, either fouling them off or putting them in play. That’s been worth a collective -133 runs, or -1.4 runs per 100 pitches.

In sum, batters have a 31.7% swing rate, and those swings cost them six runs per 100 pitches. Their takes make them six runs above average per 100 pitches. For every extra 1% of chase rate, they’re costing themselves 12 runs per 100 pitches — the difference between the juicy takes and the costly swings.

On pitches in the zone, the opposite is true. Takes are terrible, naturally. Batters take 33% of pitches, costing themselves roughly five runs per 100 takes. They swing and miss on 13.3% of pitches, costing themselves 10.5 runs per 100 whiffs. Finally, they achieve the brass ring — in-zone contact — on 53.6% of in-zone pitches, and add about two runs per 100 pitches there. Plenty of those are foul balls, which is why the number isn’t bigger, but that’s still a great result.

On in-zone pitches, batters swing 67% of the time and cost themselves 0.6 runs per 100 pitches. Their takes cost them five runs per 100 pitches. For every extra 1% of take rate, they’re losing 4.4 runs of value per 100 in-zone pitches, far less than they make by chasing 1% less often.

I’m skipping out on plenty of math there, and plenty of context. Counts matter when it comes to run values, and I’m painting with an overly broad brush by ignoring them. In these aggregates, though, I’m okay with that, and I hope that the broader point will still resonate. If the average batter could swing 1% less often at balls and also at strikes, it would behoove them to do so.

José Iglesias isn’t the average batter. Since he started swinging more frequently in 2018, he’s taking on 58% of pitches outside of the strike zone, only good for 4.2 runs per 100 pitches — he gets to three ball counts so rarely that his takes count for less. When he swings and misses (10% of the time), he costs himself 12 runs per 100 pitches. When he makes contact, he’s added a sliver of value; roughly zero runs per 100, but a positive number. In aggregate, then, an extra 1% of chase rate costs him 6.6 runs per 100 pitches, roughly half the rate of the league as a whole.

Why is that? It’s a combination of the fact that he rarely walks and the fact that he makes an absurd amount of contact. Missing out on walks and coming up empty are the two biggest reasons chasing is so bad, and they mostly don’t apply to Iglesias. He’s even a good bad-ball hitter, so the fact that he’s making suboptimal contact hurts less.

Meanwhile, he’s decidedly average when it comes to swinging at pitches in the zone. He’s cost himself four runs per 100 takes on in-zone pitches, roughly in line with the league. When he swings and misses (5.7% of the time), he loses 10 runs per 100 pitches. When he makes contact (58.7% of pitches), he gains roughly two runs per 100 pitches.

Let’s aggregate them again. On swings (64.3%), he’s gaining roughly one run per 100 pitches. On takes, he’s losing four runs per 100 pitches. Swinging an extra 1% of the time gains him five runs per 100 in zone pitches, nearly as much as he loses for an extra 1% of chase rate.

This relative valuation is rare. Most players gain three times as much by reducing out-of-zone swings as they cost themselves by swinging less in the zone. That’s why swinging less works in aggregate. Iglesias, though, has a different breakeven. If the average hitter increased their chase rate by one percentage point — swinging at one more of every 100 out-of-zone pitches — they would need to increase their in-zone swing rate by 2.9 percentage points just to break even on the exchange as a whole. Chasing is bad!

Because of his high contact and low walk rates, Iglesias looks nothing like that. If he increased his chase rate by one percentage point, he’d only need to add 1.4 percentage points to his in-zone swing rate to make it work. That’s rare territory; his skills are rare. His ability to put bad balls into play and desire to swing is more or less without parallel. Even Báez, the patron saint of swinging too much at bad pitches, isn’t the same; he misses a lot, but makes tremendous contact when he connects, a different kind of hitter entirely.

All that said, Iglesias is still swinging too much this year! Look at it in grid form, and you’ll see what I mean. The ratio column is how much his in-zone swing percentage has increased relative to his chase rate, and we already know that his breakeven is around 1.4:

It’s probably no coincidence that the year where he made the best swing decisions was also his most productive, but this year, he’s chasing too much, or swinging in the strike zone too little, two sides of the same coin. It’s still early, but knowing that his swing decisions have gotten out of balance, it’s hardly a surprise that he’s running an uncharacteristically high strikeout rate.

Could this be a sign that his bat is slowing down, that he’s resorting to guess hitting more often? It’s too soon to tell. He’s only batted 112 times, and nothing about his batted ball quality seems amiss; every Statcast metric you can name looks roughly unchanged from last year. His 87 wRC+ is dead on his career average. No, we just have a mystery: the case of the wild chase rate.

Do batters swing too much? Absolutely! Does Iglesias swing too much? This year, he does. Then again, maybe he doesn’t. Let’s take a look at that first list again, only with slightly different statistics included:

How the heck is Iglesias putting up even an acceptable line? He’s barely swinging at any strikes, and he’s waving wildly at pitches out of the zone. He hasn’t been great this year, but he hasn’t been unplayable, and that’s quite a compliment for someone with his plate discipline metrics.

Could he swing less? Sure. Really, though, what he needs to do is identify pitches at his old rate. Iglesias has a particular set of skills that let him survive despite chasing too often. If he can harness that general aggression while swinging at a more appropriate number of strikes (or swinging at fewer balls), he could be in line for sudden improvement. His ability to make contact is just that good.