I think most people who are statistically inclined instantly dismiss the concept of pitching to the scoreboard, but it's the type of idea that would be quite tedious and time consuming to disprove. Luckily, a couple of people informed Joe Posnanski that the topic was being thrown around on the Yankees broadcast and he took a crack at breaking it down:
To pitch to the score, you would need to have your team score the runs FIRST before you gave them up, right? I mean, if you give up seven runs, and your team scores three in the ninth to win, you didn’t pitch to the score did you? No, your team saved your butt. In order to pitch to the score, your team would have to score eight runs and then you would be thinking, “Well, la la la, I can give up some runs now.” Does this make any sense to anyone?
Joe takes a quick look at Morris' record in games in which his team scored one or two runs, and (surprise!) finds that he was 5-49 with one run of support and 12-37 with two runs. He contrasts this with Burt Blyleven, who has the reputation of not being nearly as adept at pitching to score despite a lower career ERA, and finds that Blyleven had far better records in both situations.
The reason I find this interesting has nothing to do with Jack Morris; I was 8 years old when he threw his last pitch. It's that one of the things that makes baseball endlessly interesting but seemingly no one wants to admit is that, despite your best efforts, you can't really control when you succeed and fail. The difference between a flyball and home run is often a few millimeters on the bat or a fraction of a second. Guys hit home runs on pitches out of the strikezone. It's not a perfect science.
If you look at WPA, which measures the leverage at the time of each at bat, you'll see that the leaders fluctuate every year. If there is such a thing as "being clutch", it certainly isn't an indelible part of someone's character or else the same people would be atop that list each season.
Like he so often does, Posnanski really nails this point:
There’s something about the long season of baseball that encourages players to believe in jinxes and superstitions and breaks evening out, something about the days turning to weeks turning to months that inspires this closely held belief that players don’t succeed because of talent or luck or even hard practice but because of character, because of a certain courage or gallantry or substance of the soul.
Part of this the collective ego-stroking you're likely to see in any elite fraternity. The fact that these guys have all risen to the top, passing hundreds of people at every level from tee ball on up makes them extremely special. It's easy to see why they feel this way. But the in the effort to find story lines, the media propogates these ideas and inner fortitude of the players is far overrepresented as a factor in success.
Sports are often described in terms of drama. A dramatic play, a thrilling climax, a heroic performance, a storybook season. However, watching sports is infinitely better than a fictional play or movie because they unscripted and unfettered. There's no need to infuse them with contrived plot twists and ascribe the players with heroic character traits. But don't try to tell that to Michael Kay and Al Leiter.