South Side Hit Pen

Reynaldo López: now or never

Full of promise and flashing elite skills, the young righty nonetheless disappointed. This dig into the numbers highlights some reasons for optimism with López — and reveals why there's some fools' gold in the stats as well.

Darren Black

Should he stay or should he go? Without solid secondaries, López won't just fall out of the rotation — he could drop off of the major league roster entirely. (Clinton Cole/South Side Hit Pen)

Reynaldo López got off to a rocky start during the 2018 season, but his numbers down the stretch were why people expected big things from him in 2019.

In 33 September innings in '18, he had a 1.09 ERA that was validated by a much better walk and strikeout numbers as well as a 2.74 FIP. Now, there was still cause for concern if you looked at expected stats, but López still seemed to be moving in the right direction; some even thought he was the better option compared to Lucas Giolito. López's off-speed pitch was working and a much better slider was getting whiffs.

Then 2019 happened.

As Giolito had a breakout, All-Star season, López faltered, only periodically showing his great potential. His fastball was still fast, but his second and third pitches lost their luster and were inconsistent at best. Among the 104 starters with at least 120 innings pitched, López had the 14th-worst FIP and fifth-worst xFIP — just about as bad as Giolito was in 2018.

López does not have that one elite pitch, but he does have that fastball that's in the 83rd percentile in velocity. He used to have a curveball, but seems to have lost that pitch to history. In terms of a new breaking pitch, it's down to the slider, and López will work in an at-best below-average change from time to time.

Now, for some good news: Because López uses so few pitches, and the fact that they are inconsistent, he is a prime candidate for a "Giolito breakout."

Let's use something simple: López's performance in wins and losses. In 25 starts, the White Sox won 10 times and lost 15. Obviously, a pitcher will have better stats when he wins a game, but for López, those stats show just how good and how bad he was.

In wins, Lopez had a 1.36 ERA, a WHIP well short of 1.000, and only allowed four homers in 66 ⅓ innings. He looked like this during his wins:

Meanwhile in losses, López's ERA was 9.58, he allowed an OPS over 1.000, and surrendered 23 homers in just 72 ⅓ innings. This discrepancy is why fans are so torn over López: Some think he is a future stalwart in a rotation, while others think he should move to the bullpen. When López is good, boy is he good — and when he is bad, he is one of the worst starting pitchers in baseball. There is a wide spectrum when it comes to López, but funnily enough, he does not do much better against winning teams than losing ones. So his fantastic performances of 2019 do not necessarily only come against bad opponents. In fact, his best start per FanGraphs game score (96) was against Cleveland. https://cuts.diamond.mlb.com/FORGE/2019/2019-09/05/4bb9eb53-1c4234c5-47343ed7-csvm-diamondx64-asset_1280x720_59_4000K.mp4 When on the bump against winning team last season, he had a 5.96 ERA, and then a 4.78 ERA against losing teams. That is more than a one-run difference, and López did have a much better strikeout rate against losing teams, as one should expect. But that doesn't tell the full story. López's OPS against winning teams (.828) and losing teams (.838) was basically the same. That was because López allowed more homers against bad teams than he did with good teams. The most likely reason why the runs allowed were more than one fewer is because bad teams are, well, bad: They do not get on base, so a big hit does not cause as much damage. That is why when you look at López's advanced splits, the tOPS+ (OPS for split relative to player's Total OPS per B-Ref), is exactly even (100) ... or evenly bad might be the better way of articulating it. Then, when you look at those splits compared to the entire league, López looks very bad. Against winning teams, López was 11% worse than average; against losing teams, he was 29% worse than average in using sOPS+ (OPS for split relative to League's split OPS). Unfortunately, a lot of that bad pitching against losing teams came from AL Central.Overall, against the division opponents the White Sox saw and will see more than any other, López combined for a 5.04 ERA. Compared with the entire league, he was also only better than league average against one AL Central opponent, Cleveland. For the rest of the division, López was not just kind of bad, he was atrocious compared to the league. In terms of sOPS+, he was 76% worse than league average against the 59-103 Royals, 50% worse against the Twins, and 35% worse against the 47-114 Tigers. Now, maybe one could say that division opponents should know opposing pitchers the best, but a pitcher also needs to have success in the division to be considered a success. There is a troubling notion, though, that carries over to other stats: Batters who see López the most do much better compared to other pitchers.It is even true when you look at it in a game-by-game basis. Now again, the third time through the order is supposed to be when pitchers start to falter. By then, batters have seen everything an opposing starter has to offer and are more or less ready for what the pitcher will throw. So of course, when batters hit against López the third time through the order, they are his worst numbers. That is not news. What is news, and what should worry fans, was that he was 29% worse than the average pitcher going through a lineup for the third time in a start. In 212 such plate appearances in 2019, batters slashed .298/.373/.548 for a .921 OPS. For comparison's sake, in 2019, Yoán Moncada had a .915 OPS and Sox fans wore more than overjoyed with how great an offensive season he had. So that's not good for López. These stats show that when batters see López a lot, whether in a single game or over a season, they punish him. And that points to the fact that maybe being a starter is not what López is cut out to be. In fact, much of the reason López had a better 2018 compared to 2019 was his weird success going through the order the third time. In '18, his best splits were against batter the third time through the order, as it was 48% better than league average. However, when that sregressed to the mean in 2019, López had an awful season. Not coincidentally, 2018 was a year where López's change and slider were actually working well; that was not duplicated in 2019, thus his troubles the third time through the order.López does not have a real breaking pitch, nor does he have a consistent off-speed offering. So it makes sense that López relies on the fastball about 60% of the time ... but a starter can't do that. A starter cannot just throw past batters all day long and hope 27 outs come, or all year long and hope for All-Star appearances, without a reliable second pitch and at least an average third. So, fans say, let's move López to the bullpen; his fastball should play well there and his inconsistencies with other pitches won't be a glaring problem:

Well, be careful what you wish for. In three of López's four seasons in the majors, he has has been worse than average compared to the league against hitters the first time through the order. Last season, he was 30% worse than average and allowed nine first-inning home runs, so maybe just throwing López in the bullpen won't be as successful as some think. Which is also why answers like these are confusing:

Yeah, more spin on his fastball is great, especially because, according to Baseball Savant, López's fastball spin rate was in the 22nd percentile. So increasing his fastball spin rate will lead to more strikeouts. But López needs to find another pitch, preferably two, that can at least be above-average to help him get through six innings. Maybe he should have Giolito show him some changeup grips and Syndergaard can give López his slider back. If López can't develop his secondary pitches, then that increased spin rate on his fastball will mean more if he's in the bullpen. To López's credit, at least he realizes his spot in the rotation is not guaranteed:

and he has a lot of pitchers, young pitchers, hungry and ready to take that spot.

It's now or never, Reynaldo.

Published
Darren Black
DARREN BLACK

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