Blue Jays And The Pitching Myth


The Blue Jays may find that the need for a plus-plus pitching staff in playoff success is overrated.

It is a truism in baseball that good pitching will beat good hitting, particularly in the playoffs.  Like many truisms, this one has a grain of truth – if your pitching staff gives up fewer runs than the other team’s over the course of a series, you have a pretty good chance of winning.  But – also like most truisms – life is not always that simple.

"Good pitching will beat good hitting any time, and vice versa. ~Bob Veale, 1966"

The World Series is frequently won by teams whose pitching and hitting get hot at the right time.  But over a short series, a pitching staff could outperform a staff which (on paper, and over the regular season) is superior.

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To illustrate this point, I did the following experiment.  For each of the past 14 years, I ranked all 30 mlb pitching staffs by team SIERA (the 14 years was chosen because SIERA was only made available starting in 2002).  I then calculated the rank of the overall World Series winner.  So, for example, in 2015 the World Series winning Kansas City Royals had a team SIERA in the regular season of 4.15, which was ranked 23rd in the majors.  I then did a similar calculation for the 8 or 10 playoff teams (for purposes of this analysis, I considered the losing wild card teams “playoff teams”). So for example, KC’s 4.15 SIERA in the 2015 regular season was the 10th best among the 10 playoff teams in that year.

My goal was to see whether the World Series winning teams were commonly those teams with the best pitching staffs in the regular season.

The results?

Postseason success by staff
Postseason success by staff /

Surprisingly, there appears to be only a weak correlation between pitching prowess in the regular season and WS wins.  The average Series winner over those 14 years was 11th in the league in team SIERA in the regular season – above average, but only barely.   And if, at the beginning of each year’s playoffs, you had bet on the playoff team with the best regular season pitching SIERA to win it all, you would have won your bet exactly … zero times.  In fact, of the 10 (or 8, prior to 2012) playoff teams, the average Series winner ranked 6th in regular season SIERA.

How can we interpret these results?

One other truism is that the playoffs are a whole new season, and that pitchers who may have struggled over 30+ starts in the regular season could (and do) get hot for 5 starts in the postseason.  Conversely, a pitcher with an excellent regular season record could struggle in the playoffs.

A second explanation could turn on changes to the pitching staff later in the year.  A mid-season acquisition might have minimal impact on the team’s overall stats for the year, but be of considerable value in the playoffs.  Or a player who was hurt for much of the season could return later in the year and dominate.  So the use of the full-year team SIERA as a surrogate for the strength of the rotation entering the playoffs could be (justifiably) criticized as overly simplistic.

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Or it might be that teams use their pitching staffs differently in the playoffs, giving more starts to their better pitchers.  So a team with a strong #1-#3 but a relatively weak #4 and #5 might have better results in the postseason with the #5 pitcher on the bench or in the bullpen.  Similarly, a team with a few exceptional relief pitchers might use those stars more frequently in the playoffs than the regular season, as wearing them out is a lesser concern.

Or it could be that the reality is that games are won by many factors – pitching, hitting, defense, baserunning, advance scouting, managing – and that while pitching is important it is only one piece of a larger puzzle.  So while elite pitching would be an advantage (and one that the Jays might not have), it is not an absolute requisite.  Elite hitting and defense are also valuable.

The bottom line

It absolutely behooves the Jays to make every effort to improve their pitching – both in the rotation and the bullpen.  But there might well be enough upside in the current rotation, combined with their potentially outworldly offense, to take them to the postseason and beyond.