Earlier this week the RotoFanatic team began our offseason coverage ambitiously beginning with the catchers. We began a two-part positional preview with the Hi/Lo Rankings debate centered on Sean Murphy. On Tuesday, I debuted our new limited series, The Data Monster Position Outliers. These articles are meant to assist users of The Data Monster and show examples of how to use it to analyze players.

Today, I will be doing the same analysis on the First Base Position. As we will do with each position we kicked off our first base coverage with a rankings debate. Michael Govier and I each took a side on Vlad Guerrero Jr. a popular pick among many to reach the levels of superstardom. While it is not longer at its heights of even earlier this decade, first base is still a premium power position. The players you draft here are likely going to guys you are counting on for around 30 home runs and ideally around 90 RBI. There still are a few players with elite AVG numbers available but the days of Miguel Cabrera and Paul Goldschmidt being first-round picks are long in the rearview. Speed can be a small differentiator at the position but Cody Bellinger is likely the only player projected to steal double-digit bases eligible at the position. So for these players, it’s all about power and run production. Let’s see what The Data Monster thinks about the big boppers.


Unsurprisingly, the leader among all first base eligible players in In_Whiff is DJ LeMahieu. Despite only starting 1 game at the position he was shifted over late in games enough times to qualify. He excels at making contact and using that contact ability and the short porch in RF to post big numbers. You are likely taking him high for his multi-positional eligibility and he is one of the few players at 1B who can potentially hit .300.

On the flip side, the first baseman with the worst In_Whiff in 2020 was Miguel Sano.

For the entirety of his career, the knock-on Sano has been his contact rate (see the above percentile ranks). However. as we can see below, 2020 was his worst season in terms of Whiff Rate. Interestingly enough, this was not driven by a change in his xWhiff rate. That has actually stayed steadily below average. Pitchers seem to pitch him slightly more aggressively than other hitters. However, we see a massive spike in In_Whiff. This value spiked once before for Sano back in 2017. The actual Whiff Rate obviously spiked with it. However, he was an extremely productive hitter in 2017 despite these issues. This was not the case in 2020 as Sano posted the second-worst wRC+ of his career. There is reason to believe he can get his Whiff rate to a more manageable number which should allow him to take advantage of his mamouth power.


As I stated in the introductory piece on Tuesday, there is not a ton of really actionable data that we can glean from looking at the In-Zone and Out-Of-Zone boards. In certain scenarios, these can help explain what makes a given player great but more often than not these tell us more about pitchers. With that being said the first baseman that finds himself the highest on the IZ leaderboard is Luke Voit. The Yankee slugger is extremely aggressive within the zone. He had a 97th percentile In-Zone Swing rate despite only a 26th percentile xSwing rate. This could be seen as an attempt by Voit to override his relatively poor Whiff numbers by eliminating called strikes. It gives me a reason to believe that he can maintain a decent average despite some K concerns. In terms of the least aggressive hitters within the zone, we find Daniel Vogelbach who has some very fringe deep league appeal. He might be better served taking a Voit like approach to this season. He should not really be on your radar.

Joey Votto has long been one of the best hitters in all of baseball at avoiding expanding the strike zone and the numbers tell us the same story. His overall swing rate dropped a ton in 2020 and it may suggest that he has further limited his attack zone to try to maximize his strengths. While he still grades as elite by my plate discipline metric (SAE) he has regressed a bit from his offensive peak and the pitches he swung at had the lowest xLwOBA of his career. There reason to see a bounceback and some CI value but I would rather go elsewhere.

The hitter who expands the zone the most at first base is Ryan Mountcastle. While the K-rate does not appear as high as I would expect from such a free swinger, this is extremely concerning for me. He swings at pitches with extremely low xLwOBA values as a whole, 8th percentile in this measure. This will mean that in order to be a high-end performer he needs to really excel on contact. He needs an elite In_wOBA value and while he showed that skill in 2020, I need a bit more of a track record before I buy-in.


The In_wOBA leader for first basemen in 2020 was unsurprisingly Jose Abreu. The White Sox first baseman was one of the best hitters in all of baseball last season parlaying that into an MVP Award.

What we see when looking at Abreu’s track record is a history of high-end offensive performance. He has arguably been one of the best and most consistent hitters in all of baseball since his debut in 2014. However, it is also clear that his 2020 season was likely unsustainably good. Despite the career stretch, his In_Whiff does not look any different than his early career and the reality is he most likely will return to those levels over a full season. However, in the middle of a powerhouse lineup, he should approach 30 homers and 100 RBIs making him a solid fantasy investment at the right price.

On the flip side, the worst first baseman was Carlos Santana. The usually reliable hitter had his first season below average by wRC+. Throughout his career, Santana has had big drops in In_wOBA only to return back to league average the next season. His main skill has always been his elite eye and 2020 was no different. His SAE was tops in the league and it gives me a reason to buy back in. He is still great a selecting the right pitch to swing at and some regression back towards league average in terms of in_wOBA should help him return to put up solid numbers for his fantasy owners.

Plate Discipline

As we already discussed Carlos Santana was the best hitter in the league by my SAE metric. Another guy who excels in this measure is Max Muncy. This is no surprise as the do-it-all Dodger has long been applauded for his plate discipline excellence. However, in 2020 Muncy seemed to regress offensively. This appears to be tied to trading LD for GB and it causing his BABIP to plummet. There was not a change in exit velocity or average launch angle but this appears to a launch angle consistency issue. Since he is so great a pitch selection much like Santana I think there is a reason to expect a bounceback but he is not a guy I have found myself owning very much of.

While not the worst first basemen by this measure, Anthony Rizzo is a name towards the bottom that stood out. While he has never been elite by the measure, 2020 was his worst season yet by SAE.

This drop does not seem to have manifested itself in a change to his walk or strikeout rates but we can also see that overall this was the worst offensive season of his career. What this change appears to be driven by is a newfound passivity at the dish. Early in his career, Rizzo was slightly more aggressive than one would expect within the zone and he has settled in right around average. However, last season his in-zone swing rate plummeted. There are many reasons that could explain why this change occurred but regardless it seems to have negatively impacted Rizzo. Hopefully, this is not the beginning of the end for Rizzo as it seems he is not the type of hitter who can afford to be extremely passive at the plate. I had previously been interested in Rizzo but after learning this information I will let someone else take the chance that he has been able to correct this issue.