Please see Part I for acknowledgments.

Let’s start with the 2009 postseason.

We take the Magic Calculator Thingy and input the following:

Innings pitched: 16.
Fangraphs’ FIP: 2.28

Next, we go to Baseball Reference and click on the ‘postseason’ tab. We look at every box score of every postseason game and add up every single run.

ESPN also has run totals here, per team, but they only go back to 2002 and we will need to (eventually) go all the way back to 1995, so knowing how to do it just looking at the BR box scores is of some use.

That gives us a total of 260 runs scored.

We then add up the total number of games played–13 in the division series (three 3-game sets, one four gamer), 11 in the League Championship Series (six and five) and six in the World Series, for a total of thirty games played.

We divide 260/30 to get a total of 8.66 runs scored per game, and we divide that by two again and get a total of 4.33 runs scored per team on average.

Whew.

We’ve got our first three variables, the fourth, park factor, has been preset at 0.975, so now we just need the fifth, the leverage index.

We’re going to use gmLI, because that’s the leverage index that gives us an average leverage number for when a pitcher enters a game, and, well, Mariano loves him some high leverage.

As we journey back to Fangraphs, we find a gmLI of 1.45, but don’t enter that in just yet. As discussed above, we need to modify it a little bit.

We do this by adding one (1.00, a neutral leverage) and then splitting the sum. That gives us our split leverage of 1.225.

NOTE: Postseason gmLI has only been calculated for the 2002 postseason onwards.  To get Mariano’s PREWARs for the years before, the regular season gmLIs will be used, minus .44–which is the average difference between regular season gmLIs and postseason gmLIs taken from the years 2002-2009.  It should be noted, however, that this figure is slightly skewed by the years in which Rivera appeared in just one postseason inning (mid 00s are chock full of these), and that the actual postseason leverage is probably a tad higher.

So we take our variables, enter them into the Magical Calculator, bada bing, bada boom, we come out with 0.542 PREWAR for the 2009 postseason.

WAIT! You say, how do you know that it works?

It’s pretty simple–plug in the values for the regular season (which uses pLI), and compare the results to the WAR listed on the Fangraphs’ leaderboard. Since those numbers are equal, we can assume they are correct and thus proceed.

So we have our 0.542 PREWAR. How does that compare to regular season WAR?

We change the IP from 16 to 70, or roughly a closer’s regular season innings, and get a result of 2.37, which is better than Mariano’s 2009 regular season WAR, though less than his 3.1 WAR in 2008 (3.1 is an utterly monstrous number for a reliever, even a closer, and Mariano’s 2008 was that good).

Anyway, so, in our PREWAR spreadsheet, we can fill in our first three columns, under the columns “year”, “PREWAR” and “converted PREWAR”.

2009: 0.542, 2.37

Now, it’s a question of doing the same for every postseason from 1995 onwards, with the exception of 2008, because the Yankees weren’t in it, and 2009, because, well, we just did that.

I’ll see you all some time next century.

****

Or at 4 PM.