ERA cannot be segregated out by situation ... you can do the math, but there is no sense in it. ERA has to do with the way pitchers handle innings, not situations. AVG or SLG or something in various situations *might* make sense, but there are a lot of variables not accounted for (thus requiring a very large sample size to guarantee randomness). If a guy faces 5-8 batters with a runner in third, it makes a lot of difference who those batters were (for instance) ... never mind the fact that there is seldom a large enough sample size in that kind of situation to generate valid stats even without batter variability. It is all nonsense. Watch the game!!
VB: Of course you have to watch the game. You've taken a ball-peen hammer to a fine Swiss watch and gilded the lily on your point. The stat is somewhat deceiving, but I was merely using it to bolster my hunch (after having watched a lot of Happ's outings) that Happ is much worse out of the stretch than he is with no one on base.
Speaking from experience (and too much of it with traffic on the paths), it is harder to concentrate and make pitches out of the stretch, which is why pitchers shouldn't do that until they have to do so, i.e., when someone is on 1B or 2B. You're splitting concentration between the baserunner and the hitter. I believe that pitching from the stretch can alter your mechanics slightly and cost you a critical few inches on a pitch that can make all the difference in the world. Why the practice is today to have relievers, who, unlike the old days, often come into games with nobody on base to pitch from the stretch is beyond dumb in my opinion--but it is something being taught in little league today. If you got an advantage from pitching out of the stretch, even starting pitchers would do so all of the time. I sure as hell would have. I needed every inch I could muster, and then some. Okay. Old crotchety fucker off of his soap box.