The Red Sox have no shortage of starting pitcher candidates on their roster for the 2015 season. With 11 players currently in the mix, the team has more than enough depth to withstand the normal wear and tear of a season.

My colleague at FanGraphs, Eno Sarris, has found that the average team needs 10 starting pitchers in any given season. But there’s a big difference between depth and quality depth, and despite the plethora of candidates willing to step into the rotation, Boston finds itself precariously thin.

Simply put, the team doesn’t have a lot of quality options. This is perhaps best exemplified by Clay Buchholz. For the past decade, we have been captivated by the inescapable highs and lows of Buchholz’s career. He has a no-hitter on his resume, and has twice been an American League All-Star. And yet, he has rarely pitched well consistently. Since 2008, his 13.3 WAR ranks just 60th among big league pitchers. His 3.98 ERA ranks 93rd out of 219 qualified starting pitchers, and his 4.09 Fielding Independent Pitching, or FIP – a metric that attempts to strip away the positive or negative effects of a team’s defense on its pitchers and evaluate pitchers on what they can control, namely strikeouts, walks, hit by pitches and home runs – ranks just 108th.

In other words, he’s middle of the pack at best.

If we focus on the past three seasons, the picture doesn’t improve. Since 2012, his 4.19 ERA and 3.98 FIP – essentially the same as his career marks – rank just 93rd and 67th, respectively, out of a sample of 121 pitchers. That’s not especially encouraging. And the bad news is that Buchholz might just be the best bet among the established starting pitchers the Red Sox currently …read more