XFIP SHOWS ACES’ VALUES TO NEW TEAMS
This year’s trade deadline did not disappoint. Troy Tulowitzki is a Toronto Blue Jay, Ben Zobrist is a Kansas City Royal and Yoenis Cespedes is a New York Met.
Perhaps the most impactful transactions, though, were the pitchers acquired by four contending teams. The Royals acquired Johnny Cueto, the Texas Rangers got Cole Hamels, the Houston Astros traded for Scott Kazmir and the Blue Jays obtained David Price. In addition to strengthening potential playoff rotations, each of those aces can be expected to add one to two wins to his new team’s regularseason record.
Two useful metrics in quantifying a pitcher’s value to the team that acquires him are innings pitched per start and expected Fielding-Independent Pitching (xFIP). xFIP speculates how many runs a pitcher likely would give up if three factors typically beyond a pitcher’s control — how often balls in play become hits, the rate at which baserunners are stranded and the rate at which fly balls turn into home runs — were replaced with league average rates. In other words, xFIP is driven by strikeouts, walks, hit batsmen and fly-ball rate.
By using xFIP, one can estimate how many runs a pitcher can save per nine innings compared to a replacement-level pitcher. By factoring in how many innings a pitcher appears in a typical start, one can estimate how many wins he is likely to add to his team’s ledger.
The value of a new acquisition should be measured not just by the runs he can prevent, but also by the marginal gain he represents over the pitcher the team can move out of the rotation.
Cueto’s arrival with the Royals exiles struggling Jeremy Guthrie from the rotation. Cueto’s xFIP through July, in 19 starts with the Cincinnati Reds and one with the Royals, was 3.43, while Guthrie’s was 5.04. While Cueto’s 2.70 ERA demonstrates that he has prevented runs better than his xFIP suggests he should, the Royals should not assume he can maintain the 8.5% home run-per-flyball rate that suppressed his ERA in Cincinnati.
Setting park factors aside, if Cueto keeps pitching 6.8 innings a start and allows 3.43 runs per nine, he should add 1.5 wins above replacement (WAR) for the Royals throughout the rest of the regular season. Since Guthrie has pitched right at replacement level, Cueto represents a 1.5-win improvement.
Hamels had a 3.18 xFIP in his 20 starts this year with the Philadelphia Phillies, far better than his 3.64 ERA. If that xFIP translates to 3.18 runs per nine in Texas, he should add 1.7 WAR. His arrival will cement the Rangers’ recent decision to designate fellow southpaw Wandy Rodriguez for assignment. Though Rodriguez struggled of late, his xFIP of 4.31 for the full season suggests that he might have added 0.6 WAR had he returned to the rotation. Hamels represents a 1.1-win upgrade.
Kazmir represents something different to the Astros. Vincent Velasquez acquitted himself well in seven turns as a starter, but he’s 23, and the club would like to limit his innings over the rest of the season. Kazmir, whose 3.71 xFIP far exceeds his 2.10 ERA-todate, should add only 1.2 WAR. Since Velasquez profiles as a 0.7win starter over the rest of the year, Kazmir’s 0.5-win upgrade is easily the smallest of the group, but Houston’s advantage lies both in Kazmir’s ability and in the value Velasquez can add as a reliever without wearing out his young arm down the stretch.
Price has been the best of the four traded aces this season, attributable in large part to the seven innings he has pitched per start. With a 3.30 xFIP, he projects to be worth 1.7 WAR down the stretch. Like Kazmir, he replaces a 23-year-old pitcher, Aaron Sanchez, who will pitch out of the bullpen. Sanchez, like Rodriguez, was sent to the bullpen before the trade, but his 4.41 xFIP suggests he could be worth half a win to the Blue Jays if they chose to put him back in the rotation. Price represents a 1.2-win upgrade in the regular season for Toronto.
Cueto, Hamels, Kazmir and Price all project to offer similar value to their teams for the rest of the season, with Hamels and Price a tick ahead of the others at 1.7 WAR. Cueto, though, might be the most valuable acquisition, since he takes the place of a true replacement-level pitcher, likely adding a win and a half for the Royals over the rest of the season.
He also should ake the mound in Game 1 of at least one playoff series for Kansas City. Maybe all three.