You probably are familiar with Cristian Javier’s performance problems in 2023. 2022 was a breakout year for Javier, and his pitching performance tabbed him as one of the top young starting pitchers in baseball. But 2023 saw Javier’s pitching numbers decline significantly, beginning with what appeared to be simple regression early in the season and graduating to more severe decline in the second half of the season.
Comparing 2023 to 2022, Javier’s strike out rate declined by 25%, his ERA increased from 2.54 to 4.64, and his x-FIP increased from 3.53 to 5.18. In 2023 Javier allowed a .236 batting average—the first time in his four year career that he allowed a batting average over .186. His previous stingy batting average allowed him to achieve good results despite a proclivity to walk batters. After allowing more hits in 2023, Javier’s WHIP increased from 0.95 6o 1.28.
Javier’s performance problem increased as the season progressed through August. His monthly ERA increased from 2.40 in May to 5.79, 6.86, and 6.17 in June, July, and August. In August, Javier allowed an OPS of .922—the equivalent of turning every hitter into Matt Olson or Freddie Freeman. However, Javier’s September performance showed improvement, as evidenced by a 4.50 ERA so far in the month.
Javier’s improvement in September culminated in the superior performance on Sept. 20, when he allowed only 3 hits, 1 run, and struck out 11 in 5 innings. This was Javier’s most strike outs since May 10, providing some hope that Javier has turned the corner.
If the quality of Javier’s pitching has returned to his early season level or even the level achieved in 2022, this could be a significant factor in the Astros’ playoff pursuits. Most likely Javier will pitch two of the nine remaining games, potentially pitching the final game of the season. Furthermore, assuming the Astros make the playoffs, a return of Javier to his previous excellence could be critical to advancing in the playoffs. Javier could slot in behind Verlander and Valdez in the Wild Card or ALDS series.
In order to explore the improvement, the pitch f/x data for the Sept. 20 game (first table) is compared to the data for Javier’s no hitter game in the World Series (second table). The World Series game presumably represents the highest level of Javier’s 2022 performance.
- A decline in the effectiveness of Javier’s 4-seam fastball (the so-called “invisiball”) is a significant factor in 2023. Although the fastball velocity has declined about 1 mph since 2022, the effectiveness of Javier’s 4-seamer is driven more by spin and vertical break characteristics. The fastball is supposed to give an illusion of “rising,” which is indicated by less vertical break (drop) than the eye expects. Although the vertical break was lower in the World Series game, the vertical break on Sept. 20 was relatively close to that game (about 0.32 inch more vertical drop). The vertical drop on Sept. 20 was less than the average for 2023 (about 3 inches less drop), as well as lower than the 2022 average (about 2 inches less drop). The 4 seam fastball on Sept. 20 was particularly effective at drawing whiffs (12 compared to 6 in the World Series game).
- Notice that Javier has added another pitch—the change up— since the World Series game. In 2023, opposing teams have begun to load their lineups with lefthanded batters when Javier pitches. And Javier has been hit particularly hard by lefties this season: OPS+ for LHB is 123 and 76 for RHB. Sliders are more effective on same side hitters (RHB), and Change Ups which have horizontal break in the opposite direction, provide more effectiveness against LHBs. Javier uses both the curve and change up predominately against lefthanded hitters.
Javier’s improvement had begun in the start (vs. the Royals) previous to Sept. 20. For the week Sept. 14 - Sept. 20, Javier’s ERA and x-FIP was 2.70 and 2.75, respectively. I compared the change in Javier’s Stuff+ over that time period. The pitch model indicates that the main improvement over those two games was related to command. Javier’s Location+ improved from 97 to 100, and his Pitching+ improved from 100 to 101. The increase in Location+ mostly involved better locating of the fastball, change up, and knuckle curve—all of which happen to be effective pitches against LHBs.
Consistent with the improvement in Location+, Javier’s strike throwing ability was significantly improved on Sept. 20. In his last start, Javier threw 68% strikes, compared to his season average 62% strikes. Since Sept. 14, Javier’s swinging strike percent increased to 17%, compared to the season average 11%.
Predicting Javier’s pitching performance has been difficult because, from the outside looking in, we don’t know the underlying causes of Javier’s second half decline. Physical injury? Mechanical issue? Fatigue? Or is it a combination of those factors?
But the improvement in Javier’s pitching appears to be real. I am cautiously optimistic that he may have corrected possible mechanical issues and found potential pitch selection strategies against LHBs. If Javier can continue the improved command and control of his pitches, this will go a long way toward a good five innings in each of his remaining starts. Given the importance of his next couple of starts, this could be a big deal.