This one promises to be extremely interesting, since Arrieta has been virtualy an unstoppable force over the past few months - he is 16-1 in his last 20 starts, with an 0.86 ERA. Let me repeat that: oh point eight six. Has there ever been such a dominant streak of 20 starts? Checking Bob Gibson's 1968 season, I did find a 20-game spell [starts 11-30], where he had an 0.79 ERA. But the run environment of that time was almost a full run lower than 2015, with the NL ERA that year below three, for the only time in the live-ball era.