Rumors swirled yesterday that the Orioles are in "advanced talks" with the Red Sox about a trade involving Jon Lester. The exact package offered by the O's was unknown, though Miguel Gonzalez was one of the names mentioned. Instead, I will focus on the other side of the rumored trade, Jon Lester, who will be a free agent at the end of the season. What will the O's be missing out on if they don't trade for him?
One thing is clear: Lester would immediately become the best pitcher on the O's pitching staff, and it's not even close. Lester is having a resurgent season, posing his highest strikeout rate since 2010 and his lowest career walk rate. He has shaved more than a run from his ERA for two consecutive seasons. Lester has outperformed David Price so far this season by both ERA and FIP, and no one debates whether Price is an ace. ZiPS projects Lester to post an ERA of 3.43 the rest of the season and Steamer projects a 3.58 ERA. Of the six current O's starters including Ubaldo Jimenez , ZiPS projects Jimenez as the best of the bunch at 4.14 ERA, while Steamer projects Wei-Yin Chen as the best of the group at 4.16 ERA. This ignores the fact that Lester is projected to pitch in a ballpark that is even more hitter-friendly than Camden Yards.
The Orioles, of course, are in the midst of a playoff race. Currently, Fangraphs estimates the O's to have a 73% likelihood to reach the playoff and 54% to win the division. Baseball Prospectus estimates the same odds to be 71% and 52%. Acquiring Lester would significantly improve those odds. Two weeks ago, Jeff Sullivan did an exercise over at Fangraphs calculating how trading for Price would affect each team's playoff odds. We can use those numbers as rough estimates on how Lester would boost the O's chances at playoff. The O's were projected to improve its playoff odds by 11% and its title odds by about 2% with the addition of Price. Lester is projected slightly worse than Price, and there are two weeks less for Lester to make an impact with the O's than when Jeff did the exercise. So the O's are probably looking at an 80% probability to make the playoffs had they acquired Lester, and about 60% chance to win the division.
These are just estimates for how Lester can help the O's reach the postseason. His impact once the O's reach there maybe even more of an incentive to trade for him. First, Lester provides the best option for the O's in a winner-take-all match if the O's fall to the wild card and are able to line up their rotation at the end of the season. If the O's reach the division series either without Lester in the wild card game or by winning the AL East, Lester would be able to make two starts in the series if necessary. Ace starters, just like ace relievers, tend to throw a higher percentage of a team's innings in the playoff as compared to the regular season, and Lester would give the O's their first ace starter since Mike Mussina.
Lester is merely a rental, and the O's cannot tender him a qualifying offer at the end of the season if they trade for him. But the O's are in a sweet spot in the playoff race and have a lot to gain from acquiring Lester. If the O's fail to complete the trade for Lester at the end of the day, you should be reasonably disappointed.