Fantasy Baseball 2021: How to determine which hitters to add off the waiver wire

Fred Zinkie
·Yahoo Fantasy Contributor
·5 min read

Although I miss some gems each season, I like to believe that I do a pretty good job of scouring the waiver wire. While drafts and trades get most of the hype, a revolving door of smart waiver-wire gems is possibly the most underrated aspect of winning fantasy baseball leagues.

Here are the criteria I use when evaluating free-agent hitters.

Playing time

A player has to be in the lineup to generate fantasy production. In mixed leagues, I’m rarely interested in players who aren’t starting at least five games per week. As an example, I would love to roster Jonathan Villar, who would be one of the top base-stealers in baseball and also a decent source of homers and runs scored if he was playing five games per week. But the 29-year-old is stuck on the Mets bench most days and will remain off my radar unless an injury to another player pushes him into the starting lineup.


This one might be the most obvious, but I am looking for good players. I am going to assess a player’s control over the strike zone, which can be seen in his BB:K rate. Players who are striking out often and rarely drawing walks are showing signs of being overwhelmed, even if they are recording the occasional homer or steal. I’m also going to look at advanced batted-ball data for those who have a recent sample size that I can trust. Hard-contact rate, fly-ball rate, line drive rate, and average exit velocity are all part of the toolbox for assessing a player’s contact tendencies.

I don’t have this luxury for newly arrived prospects, but I can learn about the skill sets they showed in the minors.

Platoon splits

Similar to analyzing a player’s recent playing time, I look for splits in their stats that will limit them to a platoon role. Joc Pederson is a good example of someone who fares so poorly against left-handed pitchers (career .565 OPS) that his upside is limited. On days when his team faces a lefty starter, Pederson will either be on the bench or drag down your fantasy stats.

Lineup spots

I try not to get carried away with lineup spots, as they can change in a heartbeat. That being said, I am often grabbing free agents for immediate help, which means that I need to be aware of their recent lineup placement. Players who hit in the top half of the lineup are going to get more plate appearances and should generate more R+RBI per plate appearance. Those who hit low in the lineup have less upside, especially those who hit seventh or eighth in the National League. I dismiss recent lineup spots when I truly believe in a player’s talent and plan on rostering him for the long haul, but otherwise, lineup spots have to be part of the equation.

Skill range

I often refer to players as having diverse skill sets, which is a major driver of waiver wire attention for me. Let’s leave runs and RBIs out of the equation for now, since they are partially team- and lineup-spot-dependent. I am generally looking for free agents who are likely to help in at least two of the other three standard categories — homers, steals, and batting average. Players with diverse skill sets are better to rely on because they can have a dry spell in one area but remain productive in the others. For example, a high-average power hitter could have a two-week stretch with zero homers but still help your team by batting .300. Players with a power-speed mix are perhaps my favorites, as they can generate counting stats in a variety of ways.


This piece of criteria matters much more in some cases than others. At times I am looking for Mr. Right and other times I’m looking for Mr. Right Now. This piece is advice more for those in leagues that use FAB or waiver priority. To make a major fantasy investment, I need to know that the player can stay in the lineup by performing well in the coming weeks. Players who are destined to go back to the bench or minors as soon as another player on their team returns from an injury are only worth a minor fantasy investment.

Supporting cast

I left this one further down the list for a reason, but to a small degree, I need to be aware of the talent that surrounds a player in their lineup. How can you not get a little more excited about someone who joins the Dodgers' impressive lineup over someone who graduates to a full-time role with the Pirates?

Upcoming Schedule

This point matters only for short-term additions, but in those cases, I want to know which opponents and venues will be part of a player’s schedule in the next week or two. Also, how many games the player’s team will play in the coming days. Here is a current example: The Blue Jays play just five games in each of the next two weeks and many of their contests are against teams with good starting pitchers. This is not the time to speculate on a Blue Jays player, whether it’s for a short-term addition or in hopes of an upcoming breakout.

Adding the right free agents is among the trickiest parts of winning fantasy baseball leagues. But if you find players who meet most of the criteria on this list, you should land several gems during the season.