Jose Quintana’s Lost Home-Run Suppression

After the White Sox traded Chris Sale, rumors flew that Jose Quintana would be on the move soon, as well. Quintana has been quite good for Chicago, but the club had no designs on contending in 2017. With four more years of control at under $40 million, Quintana was a valuable trade chip. The White Sox were right to expect a return for Quintana that rivaled their hauls for Chris Sale and Adam Eaton. Those demands weren’t met, however, and the White Sox entered the season with Quintana as their ace.

Looking at Quintana’s line so far this season — he has a 5.60 ERA and 4.28 FIP — it’s hard to imagine that his current trade value remains as high as it was this offseason. The main problem has been home runs. Let’s take a closer look.

First, some good news: Quintana has actually increased his strikeout rate relative to previous seasons. That mark stands at to 23.0% currently, higher than his career average of 20.1% and last year’s 21.6%. His walks have gone up, too, though: up to 8.6% from his career average and last year’s average around 6%. A 40% increase in walks is definitely something to note, but more alarming is Quintana’s home-run rate. Here are Quintana’s relevant home-run statistics during his career:

Jose Quintana and Home Runs
Year HR/9 HR/FB
2012 0.92 10.5%
2013 1.04 10.2%
2014 0.45 5.1%
2015 0.70 8.6%
2016 0.95 9.5%
2017 1.40 13.0%
Career 0.84 9.1%

Quintana has been pitching in a tough pitcher’s park for the duration of his career, so the regularity with which he’s suppressed home runs would appear to be a bit of a skill at this point. That said, there’s definitely been a departure this season from his established levels. His walks seem to indicate he’s not quite the pitcher he has been, but a lot of other indicators check out. His velocity seems decent enough. He’s getting first-pitch strikes. He’s pitching in the zone roughly the same amount and swings in and out of the zone don’t seem overly alarming. The home runs are only a big deal to the extent they have a tangible effect on Quintana’s stat line.

If Quintana was repeating last year’s 0.95 HR/9 and the 9.5% HR/FB rate, he would have given up seven homers instead of 10 this season. Quintana’s FIP on the season is 4.28. If we take away three homers, that FIP moves down 3.68. Moreover, Quintana’s ERA and FIP have been pretty close to each other over the course of his career. Quintana’s FIP is much lower than his ERA this season, but a lot of that is a function of a 65% left-on-base rate. For Quintana’s career, his 74% left-on-base rate is more in the vicinity of league average (73%). A league-average LOB% would result in his FIP lining up with this ERA. So if we take the three homers away and give Quintana an ERA right around his FIP, that would render him basically the same pitcher he’s been in previous seasons. Should we take those homers away, though?

We’re looking at two months of the season, and total of 10 home runs allowed instead of seven seems pretty inconsequential — especially when attempting to evaluate a pitcher with a long track record of success. Let’s take a closer look at those home runs through the lens of Statcast. Baseball Savant offers a tool with which it’s possible, by looking at a combination of exit velocity and launch angle, to determine the expected outcomes for batted balls. The table below features all 10 homers Quintana has given up this season and how often those balls become homers or outs.

Jose Quintana, Home Runs, and Statcast
Batter Date Exit Velocity (mph) Launch Angle HR% Out%
Jorge Polanco 4/9 103 26 75 11
Nick Castellanos 4/4 108 22 75 3
Mookie Betts 5/30 108 21 59 8
Deven Marrero 5/30 103 23 49 12
Jake Lamb 5/24 99 27 44 39
Brandon Guyer 4/21 101 24 42 17
Hunter Renfroe 5/14 101 30 35 51
JaCoby Jones 4/4 98 32 29 62
Ian Kinsler 4/4 99 36 26 73
Deven Marrero 5/30 96 28 17 73

Looking over these homers, we find that he’s given up some that weren’t of the cheap variety. At the bottom of the list we see a few that were unlikely homers. Based on the above, we might be inclined to believe there was just some bad luck, that maybe Quintana’s skill in preventing homers isn’t quite gone.

Absent from the above list, however, is those batted that maybe “should have” been homers but weren’t. In an attempt to capture these plays, I did a search on Baseball Savant for batted balls that Quintana has allowed on which the expected ISO was greater than .750. I chose .750 because that’s the point where half of the batted balls are home runs. This search should pick up on any batted balls that should have been home runs but didn’t end up leaving the park. Here’s that table:

Jose Quintana and Statcast
Batter Date Exit Velocity (mph) Launch Angle HR% Out% Result
Paul Goldschmidt 5/24 107 20 49 8 2B
Alcides Escobar 5/2 99 30 41 49 FO
Joe Mauer 4/15 101 22 20 35 LO
Chris Gimenez 4/15 100 23 19 29 2B
Nick Castellanos 4/4 108 18 17 25 LO
Austin Jackson 4/21 105 18 4 33 2B
Max Kepler 4/15 105 18 4 33 2B
Non homers where expected ISO was at least .750 based on launch angle and exit velocity

It looks like he almost gave up a homer to Paul Goldschmidt, which is understandable, and that he almost gave up a homer to Alcides Escbar, which is less so. For the most part, it doesn’t seem like we have any particularly unusual results. It’s possible that Quintana has gotten a bit unlucky on homers. When we look at xwOBA compared to wOBA, it appears that Quintana has had some bad luck: his .314 xwOBA is much lower than his wOBA against of .345 this season. In both 2015 and 2016, the difference was just eight points, which is in line with pitching in a hitter’s park on the South Side of Chicago.

If we take a closer look at the dates on those home runs, we should note that six occurred in his first and last start, combined. In the nine starts in between, Quintana put up a strikeout rate of 25%, a walk rate of 9%, a HR/9 of 0.64, a HR/FB of 6.3%, a FIP of 3.07 and an ERA of 4.31 due to at 67% LOB rate. That’s pretty good.

When we note the potentially declining trade value of Jose Quintana, are we making too much of three extra home runs? Maybe. We shouldn’t ignore those two poor starts, and we should take notice of those extra home runs and those extra walks. As for trade value, it probably has declined — Quintana hasn’t pitched all that well this season — but it wouldn’t be too big of a surprise if he pitched as expected the rest of the way, helping the White Sox acquire more in a trade and another team contend for a playoff spot.

Craig Edwards can be found on twitter @craigjedwards.

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Based on the 17 batted balls provided, the expected number of HR based on the HR% for each is 6.05, which is actually less than the 7 you get using his career HR/FB%. The odds of him giving up 10 or more are 2.69% based on the same calculation.

Now, obviously there’s more to factor in here (stadium, weather, etc.), but based on those numbers, his skill at preventing the HR is as good or better than it’s always been.

Choos on first
Choos on first

But what happens when the weather gets warmer and the ball travels farther?

formerly matt w
formerly matt w

One thing about this is that the numbers for those 17 batted balls don’t comprise all the batted balls off him that might have been home runs. For instance, on April 21 Jose Ramirez hit one that was within .2 MPH and .2 degrees of Kinsler’s, so like Kinsler’s it had a 26% chance of being a home run and a 73% chance of being an out. Which means it doesn’t show up on Craig’s query, since the xISO is… well, hmm, the xISO should be a bit above .750, but it doesn’t show up.*

Anyway, if you’re going to add up the HR% to get an expected number of HRs allowed, you should include balls like this, which are usually outs but if they aren’t outs are HRs. ‘Cause if you give up four balls like this, you’ll give up 1 HR on average, but it’ll look like you gave up one unlucky one and got three outs that should’ve been outs. The balls in Craig’s second table with a low HR% are screaming line drives that usually hit the wall.

That said it doesn’t look like Q has given up a lot of these usually-outs-but-sometimes-HR hits; it looks like most of the fly balls between 30 and 50 degree launch angle aren’t hit that hard.

*OK, I’m confused by Craig’s statement that a ball with an expected ISO of .750 is one where half the batted balls are home runs. The ISO of a home run is 3.000, so if the ball has a half chance of being a home run, the xISO should be at least 1.500, amirite? What am I missing?


his skill at preventing the HR is as good or better than it’s always been

Does he have that skill? Aside from 2014 he’s been around the 10% that is pretty standard for starting pitchers.


I don’t think that number is scaled for playing in a small stadium, and I thought the average was a little higher (like 12%)? I might be wrong on both those points.