October Impact Rankings: Top 40 players in 2023 MLB playoffs


The MLB postseason is always an unpredictable, chaotic, messy and wonderful affair. No, we don't know who is going to win (although the Atlanta Braves are as heavy a favorite as we've seen in a long time after winning 104 games with one of the best lineups ever). We also don't know who will step up as an October hero. Sometimes it's the superstar carrying a team -- Bryce Harper has done it -- and sometimes it's a journeyman outfielder like Eddie Rosario (who shone for the Braves in 2021) or a rookie shortstop like Jeremy Pena, who was the World Series MVP for the Astros last year.

We can, however, make reasonable forecasts on the players most likely to make the biggest impact over the next month. Here's what I did. I took each player's regular-season WAR (the average between Baseball-Reference and FanGraphs), adjusted it for playing time (so a player like Harper, who missed time in the regular season but will play every day in the postseason, isn't penalized) and factored in how deep a playoff run is expected from his team (using my colleague Brad Doolittle's odds, based on 10,000 postseason simulations).

I made a couple of tweaks to a player's WAR. First, I weighed a player's offensive contribution a little more. Not because defense isn't still important in the postseason -- it is! -- but because offense is so hard to generate. The overall batting average last postseason was .211 and the OPS a meager .649. In 2021, teams hit .244 with a .709 OPS. So those players who do hit can often have a bigger influence on the playoff outcomes. Likewise, all the extra off days mean a team's best starters and relievers pitch more often than in the regular season, so I gave them a value boost, as well. Last season, for example, Framber Valdez's percentage of innings for the Astros increased from 13.9% in the regular season to 19.8%. Zack Wheeler went from 10.7% to 23.8%. In 2021, Max Fried went from 11.8% to 19.8%. Relievers might come close to doubling their percentage.

All of that means this isn't a ranking of the 40 best players in the postseason! Great players we think won't play long will be lower on this list. Instead, you get this: our list of the 40 players ready to make the biggest impact this postseason. The top guy is no surprise.