Let’s use strikeouts minus walks divided by innings to get a sense of which guys because of these foundational stats are underachieving in ERA (should be lower) and which are overachieving (ERA should be higher). And we’ll use our data from MLB-stat provider Inside Edge for deeper dives.

Currently the average of the qualifying starters in our (K-BB)/IP stat is 0.61. The top 10 in the stat have an average ERA of 2.44. The bottom 10: 4.96. The middle 10: 4.12. So the stat generally correlates to ERA. This makes outliers the pitchers we need to examine more closely.

First the pitchers who should be helping us a lot more according to the model but who are struggling in ERA instead:

Jon Gray has 76 Ks and just 19 walks in 65 innings for a (K-BB)/IP of 0.88. Yet his ERA is 5.68. Inside Edge gives him a C-minus, which I’ve pointed out given the same grade for Luis Castillo is not mixed-league worthy. His well-hit average allowed is .139 (.155 is average). We should expect better given that swing-and-miss stuff. His percentage of runners who score is 35% though, where 20% is league average. So there is a lot of bad luck in his ERA. And his BABIP allowed is .380, the worst in baseball. However, he pitches uphill in Colorado, so is the reason for his struggles? Sort of. His ERA at home is 6.45 but on the road it’s not playable either: 4.61. I can’t see rostering Gray even for the Ks.

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What about Dylan Bundy (83 Ks and 20 BBs in 68.2 IP, 0.92 in the stat)? Let’s ignore the report-card metrics that deal with runs since we know the ERA (4.46) is bad. He’s about an A-minus in Working Ahead/Command. His dominance would be in the same place if not for the troubles with 1-2-3 innings (just 37% of completed innings, league average). His well-hit is disappointingly average. His expected problem is so many games against the Yankees and Red Sox. But he’s been okay in two starts against the BoSox (3.86 ERA) and hasn’t faced the Yankees yet. Again, with pitching, location, location, location. His park is doing him no favors (4.78 ERA at home). I’d pass on Bundy too and pick up the most available of the three major outliers….

No, I just can’t quit Vincent Velasquez (49 strikeouts minus walks in 57.1 IP). He’s a C-plus, according to Inside Edge but would be a solid B if we just backed out the runs stats (his ERA is 4.08). Yes, this includes a B in Command/Working Ahead. Most impressively, he gets an A-plus in both well-hit allowed (.095) and well-hit of strikes (.033). Want more? His OPS allowed to the heart of the order this year is a league-best .433 and 3-4-5 hitters have collectively hit the ball well in four of 80 at bats vs. him. All hitters in the last month are missing nearly twice as many of his pitches in the strike zone (27.8%, league best in the period) than average (15.5%). Sure a lot of this is pitching in a weaker division but that’s what we want. He’s still just 32% owned in Yahoo leagues. I know I write about Velasquez all the time but he pops up in most models of guys who should be A LOT better.

Now for the fun part where the owners of pitchers who are doing well just lose it because our strikeout and walk model says they are greatly overachieving:

Gio Gonzalez has 35 Ks minus walks in 64.1 innings. His ERA should be about average, not 2.10, right? Well, not so fast. He’s a ground-ball machine. The heart of the order this year hits the ball on the ground 73.1% of the time against the lefty. So he doesn’t need Ks to suppress runs. And his overall well-hit allowed is only .120 so they’re not even hitting hard grounders. He’s not efficient. He has poor command and control. He doesn’t get enough Ks. But he is likely to remain a plus in ERA for the balance of the season, and a solid source of wins. I get an expected ERA right now for him of just 2.80 normalizing percentage of base runners who score. Gonzalez is a hold.

Jon Lester and Michael Wacha have identical 2.71 ERAs through Wednesday and are both subpar in Ks and walks (0.51 and 0.44, respectively). I can’t more strongly endorse selling Wacha. He is getting hit hard (.169), pounded on off-speed stuff (.114 vs. league average of .047), his command and working ahead are (D-plus for each) lacking and he’s inefficient (worse than average in three-ball counts, first batter retired, at bats of four or less pitches). I’d be shocked if his ERA the rest of the year was under 4.00, never mind under 3.00.

Lester seems like a tougher call because it’s really based on one stat. His well-hit allowed is .185. Sorry, I just can’t tolerate a D-minus in this most-important measure of pitching effectiveness. I have no idea how Lester is defying the odds this year but it is very unlikely to continue unless he figures out how to have hitters barrel the ball much less frequently. And he’s far from a command/control guy. Sell Lester’s ERA if you can, too. Lester and Wacha have very marketable fantasy stats. They just probably won’t remain marketable for long.