Part 1 was Explaining The 1959 White Sox. There I showed that the White Sox had a much higher winning percentage than their underlying stats would indicate. Here I try to quantify how much their clutch performance helped. They had an actual winning percentage of .610.
But according to my study from a few years ago called Does Team Clutch Matter in Baseball?, they should have only had a pct of .522 based on their OPS differential. The Sox only had an OPS differential of about .020 since their hitters had an OPS of .691 while their pitchers allowed an OPS of .671. My team clutch study had a regression equation for winning pct of
(1) PCT = 0.49 + 1.27*OPS - 1.26*OPPOPS
That projects a team with an OPS differential of .020 to have a pct of .522. So how did the Sox end up with a .610 pct? Another regression equation was
(2) PCT = 0.501 + 0.918*NONCLOPS + 0.345*CLOPS - 0.845*OPPNONCLOPS - 0.421*OPPCLOPS
That is, OPS by the hitters and OPS allowed by the pitchers was broken down into "close and late" (CL) situations and non-CL situations. Here is where we can start to see how the Sox had such a good winning pct. Their hitters had a CL OPS of .742 and a non-CL OPS of .680. For the pitchers, those numbers were .623 and .682, respectively. Plugging those numbers into equation (2), the Sox would have a pct of .543. So it is possible that their superior CL performance (especially compared to nonCL), added about .021 to their pct. That is about 3.2 wins over 154 games.
The Sox also did extremely well with runners in scoring postion (RISP). Their hitters had a RISP OPS of .742 and a non-RISP OPS of .673. For the pitchers, those numbers were .639 & .680. How did this RISP performance affect their winning pct? Equation (3) estimates that. It is like equation (2), but broken down by RISP and non-RISP performance.
(3) PCT = 0.501 + 0.848*NONRISPOPS + 0.432*RISPOPS - 0.799*OPPNONRISPOPS - 0.462*OPPRISPOPS
It projects the Sox to have a pct of .553, .031 better than the .522 estimated by equation (1). Over 154 games, that is about 4.77 wins.
It is not clear how to combine the information generated by equations (1) and (2). I am not sure if we can simply add the .021 to the .031 to get .051 and then say that their clutch play add that much to their pct. There is going to be an overlap between the CL and RISP situations. Usually about 25% of plate appearances (PAs) are with RISP and about 15% are CL. Just multiplying the .25*.15 would get about .0375, meaning that 3.75% of PAs are both CL and RISP. So maybe their would not be much overlap and summing the .021 & .031 is okay. Maybe not. I'm just not sure.
But it could be that the combined RISP-CL situations are extremely important and maybe the Sox did well in those cases, further adding to their pct. Anyway, if we could add the two gains together, it would explain more than half the unexplained gap from equation (1), which was .088 (.610 - .522). Whatever the case, the Sox had no advantage over their opponents in non-CL and RISP situations but totally dominated when it was CL or RISP. This is probably the reason for their success. Since no one seems to know how to consistently perform well in the clutch, we have to view the 1959 White Sox has having been very lucky.
I also found that their starting pitchers allowed an OBP of .306, not counting sacrifice hits and IBBs. The starters had allowed 2.26% of hitters to hit HRs. These numbers for the relievers were .306 and 2%. So it could be argued that the White Sox had a great bullpen and that explains the great pitching performance in CL situations. But that is not the case.