Identifying the Starting-Pitcher Buyers

Over the next month, rumors will shape baseball coverage, and a small portion of those rumors will actually develop into real trades. Every team with a shot at the playoffs wants to get better, and adding a starting pitcher is often the mode for many organizations. Even teams that have pitching could probably use a little more. To be willing to part with organizational resources, teams need to have an appropriate nexus between the impact of the new pitcher and a spot on the marginal win curve that makes the upgrade worthwhile.

Eliminating buyers is harder than finding them at present. Every team in the American League except for the Chicago White Sox, Texas Rangers, and Oakland Athletics have at least a 15% chance of making the playoffs and even those three teams might not have thrown in the towel yet this season. Only the Kansas City Royals, New York Yankees, and Los Angeles Angels have greater than a 55% chance of making the playoffs and even those teams do not have commanding leads in their respective divisions. The National League looks slightly more clear with seven teams likely fighting for five playoff spots. In a tight race, a pitching addition can have a considerable impact, but how much difference a trade makes depends on the hole the new player is filling.

A quick look at the rest-of-season depth-chart projections reveals how rotations are expected to perform in the second half. The graph below shows the projected WAR for all Major League Baseball rotations.

Eliminating teams without at least a 20% chance of making the playoffs, the graph looks like this:

Baltimore, Kansas City, and Toronto appear most urgently to require an upgrade. With just three wins expected over the course of rest of the season, the Royals appear to have a lot of room to improve by adding a starter, but they might not even need to make a move. The Blue Jays have had problems filling out their rotation all year long, and could be candidates along with the Orioles, but taking an overhead look at the rotation does not show the proper picture.

Looking solely at total rotation WAR can be be misleading. Any pitcher that comes in does not improve slots one-through-four in the rotation. The new pitcher takes the innings of the vacated fifth spot, and while acquiring a “number-two” starter technically slots pitchers 2-4 into spots 3-5, the difference in performance comes from removing the departed fifth starter’s innings. For most teams, those fifth starters are an amalgam of several pitchers as teams use multiple pitchers to fill out the rotation.

Over the course of the rest of the season, every team will have starters pitch roughly 450 innings. While the top four pitchers in any rotation will carry a heavier load than the fifth starter, dividing the roles into 90-inning chunks per starter slot provides a basis for determining team improvement. We can determine roughly how much production will be removed if a new starter is added by tallying a team’s last 90 innings. The graph below is not restricted to any one player, but the final 90 innings from a team’s starters according to FanGraphs Depth Charts.

Restricting the list to the contenders above, the graph below shows projected fifth-starter WAR for those teams that could be looking to upgrade.

The team’s at the right of the graph are in pretty good shape. The Mets’ young starters, along with Bartolo Colon, capably fill out that club’s rotation. The Washington Nationals continue to have strong pitching, while the Los Angeles Angels, St. Louis Cardinals, and New York Yankees likely would not benefit from an addition absent a major upgrade. The next highest team on the list is a bit puzzling.

Kansas City has the lowest projected rotation WAR among contenders but one of the higher fifth-starter projections. The problem for the Royals is that Yordano Ventura is projected for one win the rest of the season, but no other pitcher is projected for more than 0.6 WAR, with potential fifth starters Danny Duffy and Kris Medlen potentially outperforming current rotation members Edinson Volquez, Jeremy Guthrie, and Chris Young. The Royals could make a big trade and displace a current member of their top four. Chris Young could be the most likely candidate, as his ERA has crept over four for his last ten games to go along with his seemingly always higher 4.76 FIP. The Royals could make a mid-level move and potentially gain a win, but unless they disrupt the rest of their current rotation, only a major change or multiple smaller changes would have a significant impact.

Consider the projections for potentially available starters (sorted by rest-of-season WAR):

Pitcher	IP	ERA	FIP	WAR
David Price	101	3.39	3.12	2.2
Johnny Cueto	97	3.04	3.34	1.9
Cole Hamels	84	3.39	3.35	1.6
James Shields	89	3.42	3.36	1.5
Jeff Samardzija	94	3.93	3.64	1.5
Scott Kazmir	74	3.63	3.50	1.1
Mat Latos	79	3.68	3.54	1.0
Yovani Gallardo	88	4.24	4.09	0.9
Mike Leake	90	3.99	4.01	0.9
Dan Haren	68	4.13	3.99	0.7

Mid-range starters will not make an impact unless a team has a gaping hole. That brings us to the Tigers. They are unlikely to be sellers, but David Price’s name was included above for perspective, because if they did decide to sell, they would have the best pitcher on the market. The Tigers’ current fifth-starter situation creates a bit of a dilemma. The Tigers are only a .500 team, but projections for the fifth starter are so poor, they could make an impact move and make themselves the favorites for one of the wild cards while even a decent pitcher would give them a much better shot than the 26.5% playoff odds they currently own. Detroit has not shied away from big moves in the past and has remained intent on staying in contention.

Cleveland presents something of a surprise. They ranked very highly among rotations’ expected WAR going forward with the third-highest total, but they could improve their rotation significantly by adding a solid fifth starter. Unless they believe Cody Anderson can continue to suppress runs without striking hitters out, a fifth starter could really improve Cleveland’s chances. Tim Hudson’s return should help solidify the Giants’ rotation, but for the Red Sox, Blue Jays, and Cubs, a significant upgrade could improve their chances down the stretch if those teams choose to stay in the race.

Not every starter will make sense for every team. For some, like Detroit, almost any addition will do. For teams getting decent production, only a major upgrade is worth giving up young talent. With so many buyers for top talent and very few sellers, teams will face difficult decisions when attempting to upgrade their rotations.