Let's not get ahead of ourselves. To realize the magnitude of Hershiser's accomplishment, consider that Webb is barely past halfway to the record.
But for fun, let's compare the first four games of Webb's streak to the first four games of Hershiser's. Webb's streak actually began in the last inning of a game. Hershiser's streak actually began in the 6th inning of a game in which he pitched the distance. The data below for Webb and Hershiser includes the first four games they started after the streak began in those partial games.
PC is pitch count. GS is the average pitching game score using Bill James' methodology. RS is run support for the pitcher. And sOPS+ is the relative OPS+ plus for the opposing team, taking into account the team's home/road splits.
IP H BB K PC GS RS sOPS+
Webb 32 21 6 29 440 77 15 94
Hershiser 36 21 6 29 417 82 9 85
That's pretty interesting. Hershiser is more dominant, having thrown 4 complete games and achieving a higher average game score as a result. But 1988 was a different era. While complete games were waning, they were still more prevalent at that time. In 1988, nearly 14% of games were complete games. In 2007 so far, only 2% are complete games. Can't really ding Webb for that.
What's amazing is that they have the exact same number of hits, walks and strikeouts, albeit in a different number of IP. Hershiser was more efficient, throwing 6 fewer pitches a game. Webb also has gotten better run support, though 8 of those runs came in one game.
I'm not sure if run support helps the streak or hurts it. Lots of run support might relax the pitcher. On the other hand, is relaxation good for a scoreless streak? I think probably not. Hershiser was the bulldog, and I think he thrived in those competitive scenarios.
The most interesting figure is the sOPS+ figure of the opponents. Hershiser's opponents were terrible at the plate, producing at only 85% of league average. Webb's are also poor at 94%, but not nearly as bad.
So although Hershiser's stats are slightly more dominant, some of the statistical diffference can be attributed to (1) the era when there were more complete games and (2) weaker competition.
To see how that bodes for Webb in his next three games, let's see what Hershiser did in his last two games of his streak.
IP H BB K PC GS RS sOPS+
Hershiser 19 9 3 5 228 82 3 94
He got tougher on baserunners, and maintained a high average game score (which isn't hurt by a 10 inning complete game). His competition was a little better...about where Webb's has been. But Hershiser's pitch count per game rose by 10 pitches a game and his strikeout rate plummeted. Perhaps that's the quality of the competition kicking in. Interestingly, his run support continued to be horrible.
Webb's going to need at least three games to reach Hershiser's record. If the rotation holds up, he'll be at Atlanta, home against Milwaukee and at San Diego. Their average sOPS+ (as of now) is 93, but that's a deceiving number brought down by San Diego's 76 at home. Atlanta has a 100 at home and Milwaukee a 104 on the road.
To the extent run support is a factor, Webb might have an advantage. Atlanta, Milwaukee and San Diego (especially) have some quality starters that may keep the games close.
But until he gets past Atlanta and Milwaukee, it will be hard to convince me that something is better than Orel.
