With all the talk of the MLB playoffs being a crapshoot recently I got to wondering:  Compared to the other major American Sports, are the MLB playoffs more, less, or just as predictable as playoff outcomes in other sports?  Using the data from all four major sports' playoffs since the introduction of the wild card in baseball.  Here is what I came up with:

Average Champion's Seed Here is the Average seed of champions in all major American sports since the 1995 MLB playoffs:

MLB: 2.25

NFL: 2.625

NBA: 1.6875

NHL: 2.13

As can be seen, MLB champions since 1995 actually have the third highest average seed among the other sports.  What shouldn't be forgotten, however, is the fact that other sports invite more teams into the playoffs which increases the chances of a higher seed  winning the title.  In an effort to curtail this, I adjusted the other three sports' champions' seeds to represent a rough equivalent  of what their  seed would be in the MLB playoffs.  So for the NFL playoffs a 1 seed was still 1, but a 2 seed was 1.6, a 3 seed 2.2, and so forth.  For the NBA and NHL, a 2 seed was 1.4, a 3 seed was 1.8, and so forth.  Here is what I came up with for adjusted champions' seeds:

MLB: 2.25 

NFL 1.975

NBA: 1.25

NHL: 1.493

Using this adjusted seeding model, the MLB has the lowest seeded champions.  Therefore while on average the MLB champion is a higher seed than the NHL and NFL champion, that's more a result of the MLB having fewer teams in the playoffs in the first place.

Average Finalists' Seed

Here is average seed of the finalists in their respective sport since the 1995 MLB Playoffs:

MLB: 2.375

NFL: 2.21875

NBA: 1.96875

NHL: 3.1

As can be seen, the MLB has the third highest average finalist seed of any of the four major sports, and that's even with fewer lower seeded teams than any of the major sports.

Early Round Upsets

How common is it for a lower seeded team to beat a higher seeded team in the playoffs?  Here are the percentages for every sport since 1995, omitting the championship game or round of each sport :

MLB: 43.75%

NFL: 34.375%

NBA: 23.661% 

NHL 33.333%

On this one it isn't even close.  A playoff upset in the MLB is clearly more common than any other sport.  Then I got to wondering, are the other sports' averages driven down by are the averages of other sports driven down by the fact that there are more early round games with higher seeds beating lower seeds?  Here is the percentage of lower seeds beating higher seed teams in each of the sports quarterfinal and semi-final rounds (effectively their division and championship series) since 1995:

MLB: 43.75%

NFL: 29.166%

NBA: 27.083%

NHL: 36.666%

So, while the NHL and NBA see a slight increase in percentage the MLB still has the most upsets in quarterfinal and semi-final rounds.  That and the NFL percentage actually goes down dramatically so a lot of their upsets occur in the wild card round.

So in short, yes, even compared to other major American sports the MLB playoffs are a crapshoot.  Even with less teams involved baseball has just as many lower seeded champions and a lot more upsets in their playoff rounds.  Major League Baseball has what other sports purport: more parity and more drama in their playoffs, and all of this with even fewer teams involved.