“Always Draft NL Pitchers” | Fantasy Baseball Strategy Analysis

Without much thought into it, I’ve always tried to acquire NL pitchers over AL pitchers in my mixed fantasy leagues.  The thought process never matriculated very far past the fact that the league ERA would be lower in the NL than the AL.  So, if two similarly leveled pitchers were out there, I’d side with the NL one over the AL instinctively.  Given the fact that I never really looked into it, it seems like it is high time to test out the theory.  It may not be a popular strategy for fantasy owners but it’s worth looking into nonetheless to see if it holds any weight.

The first premise in the theory here is that the National League would have a better environment for fantasy pitchers than the American League.  This is fairly obvious given that there is no DH and that facing off against a pitcher in the 9 hole a few times a game will lend to a few more strike outs, better WHIP and better ERA.  But, just how drastic is the difference in those specific areas?

• 2010 NL 4.02 ERA; 1.348 WHIP; 7.4 K/9
• 2010 AL 4.14 ERA; 1.346 WHIP; 6.8 K/9
• 2009 NL 4.19 ERA; 1.378 WHIP; 7.1 K/9
• 2009 AL 4.45 ERA; 1.403 WHIP; 6.9 K/9
• 2008 NL 4.29 ERA; 1.391 WHIP; 7.0 K/9
• 2008 AL 4.35 ERA; 1.391 WHIP; 6.6 K/9

Over the past three years, the league ERA has slightly favored the NL (with 2009 heavily favoring the NL).  But, surprisingly, the difference is only a few percentage points.  With WHIP, the difference is even less drastic aside from 2009 and the AL even beat out the NL in 2010.  However, the strikeouts seem to more heavily favor the NL which is likely aided by facing off against the opposing pitcher a few times a game.

Though the difference for the entire league may not be drastic, the MLB leaderboards may tell a different story.  In the past two seasons, 7 AL pitchers finished with an ERA below 3.00 while 19 NL pitchers accomplished the same feat.  Meanwhile, 9 AL pitchers finished with a WHIP below 1.15 and 16 NL pitchers did.  And, finally, there were only 6 AL pitchers that finished above a 9.00 K/9 rate while 15 NL pitchers did.  So, even if the league as a whole doesn’t illustrate a stark difference, the more elite starting pitcher numbers reside in the NL.

Though we can all agree that the NL is a better league for pitching, fantasy leagues clearly may have already adjusted to this by having more NL pitchers in the early rounds.  If this is the case then fantasy drafts have already reacted to the change and my point is moot.

Looking at sheer quantity, there are 3 AL starting pitchers currently being taken in Rounds 1-4, 8 in Rounds 5-8 and 11 in Rounds 9-15 (NL had 4, 11 and 12 respectively).  So, there are a few more NL pitchers being taken but it’s certainly not a drastic difference in any of those regions.  However, logic would have us assume that the AL players taken in these rounds are comparable to the NL pitchers taken in those same rounds.  Let’s take a peek though.

Using the currently available projections of Marcel and Cairo, we can analyze how many roto points specific pitchers contribute to your fantasy teams in ERA, WHIP and K specifically.  Taking that previously mentioned pool of pitchers in those three areas of the draft, let’s compare how they are scheduled perform this season.  The following chart shows the average predicted roto point value that starting pitchers are projected to contribute for ERA, WHIP and K’s specifically.

In the first four rounds, there is a small difference between AL and NL but it could be attributed to small sample size.  In the next four rounds, the difference grows to over one roto point worth of difference between AL and NL pitchers in this same area.  Over the next six rounds, the pitchers become more marginal but the difference between AL and NL pitchers is still over one roto point over these three roto categories.  Out of all 50 of the SP’s being drafted in the first 15 rounds, the average difference between AL and NL pitchers is more than 1.5 roto points.

When we’re in each of these regions of the draft early on, the assumption is that we are comparing similarly valued pitchers even if they’re AL or NL but their actual results do not show that assumed similar value.  It can be seen that the current market doesn’t necessarily distinguish the difference in leagues between pitchers despite an obvious difference in performance.  In other words, NL pitchers are being undervalued on the whole and this seems to be a market inefficiency.

When your decision is between Felix Hernandez or Roy Halladay, the difference is less severe than when it’s between Ted Lilly and A.J. Burnett or Hiroki Kuroda and Ricky Romero.  So, pick your battles wisely.  But, when you’re stuck between a couple of pitchers that you can’t quite decide on, we can see that it doesn’t hurt to lean towards the NL pitchers first.