Recalculating Player Value: Jansen, Turner, & Weaver

With the season underway, owners need to start adjusting some player’s fantasy value. Some of the tweaks can be from talent changes (e.g. increase in talent) or role (e.g. moving for a long reliever to starter). Three players, Kenley Jansen, Trea Turner, and Luke Weaver, are three such players on the move.

Kenley Jansen

The concern with the 30-year-old righty is his fastball (cutter) velocity dropping from 93.3 mph to 91.2 mph.

The news has improved over the past couple days as the velocity has trended up. He may or may not be able to keep the gains and we don’t know where his talent will level out. Even without this information, his talent can be estimated at a lower fastball velocity for future reference.

The key behind estimating his talent is finding his cutter results at different velocities. By grouping his cutter results into 1 mph increments, here are its swinging strike rates over the past three seasons.

The slope is steady with a r-squared of .98 and the SwStr% equation of:

SwStr% = .0204*FCv -1.74

The next key is to give the pitch an ERA based on its SwStr%. This procedure can be done using my pERA metric with gives each pitch an ERA value and combines them for an overall ERA estimator.

Assuming a steady 32% GB% on the cutter, here’s it’s projected ERA at different velocities

With the new cutter pERA, I just have to make a few talent assumptions to estimate Jansen’s overall value. The assumptions are:

• His slider will remain as effective (0.00 pERA)
• His pitch mix will stay the same (90% cutter, 10% slider). He’s closer to 85%/15% this season.
• Maintains the same amount of control (BB% constant, -0.3 to his ERA)

And here are the results:

The results are not catastrophic if he loses 2 mph but he moves from elite status into more of a middle-of-the-pack closer. Greg Holland had a similar decline from his Royals peak with back-to-back sub-2.00 ERA seasons with a 96-mph fastball to the past couple seasons with a 93.5 mph fastball and a 3.50 ERA.

Jansen may keep up his last appearance’s velocity and be his old self. If not, fantasy managers need not freak out as he’s likely to still be a decent closer.

Trea Turner

Last week I wrote about Trea Turner moving down in the Nationals lineup. Now, I’m finding out how much fantasy value it cost him.

This calculation is easier after I created a simple tool earlier this offseason to estimate counting stat changes. Making the assumption Turner will playing 90% of the Nationals games and the team scores 5.0 Runs per game, his here are the projected Runs and RBI’s from the 1st and 6th lineup spots.

The Run+RBI total stays constant has the Run total switch over to RBI’s. An owner may be forced to deal with this change later in the season with a trade to balance their team.

The biggest difference is in the plate appearances. According to our projections, Turner was expected to steal a base once every 12.6 PA. He’ll lose the opportunity for about 6.5 steals over the course of a season. Eyeballing the difference in six steals with our auction calculator, his value drops about $1.5 in a 15-team league. Decent but not huge.

There isn’t much Turner’s owners can do about the move though. If they drafted him for steals, they aren’t going to find a 40+ stolen base guy on the waiver wire. They are just going to have to ride out the move.

Owners in point based leagues like Ottoneu will be hurt the most as the 80 fewer plate appearances will affect his total points. Those owners may be able to move him at his preseason full value.

Luke Weaver

After digging around this preseason and into the season to find pitchers with effective new pitches, I was only able to find German Marquez. I now have a second one, Luke Weaver, and his hard curve. While he did throw a curve last season, this one is 2 mph faster and he’s using it 20% of the time.

Here’s a look at the pitch.

This pitch makes him better for a couple reasons. First, it gives him a third pitch to help him navigate a lineup multiple times as hitter can’t just sit on his fastball and change.

Second, it’s a breaker he can throw for strikes if behind in the count. His changeup is a great swing-and-miss pitch but it’s rarely in the strike zone (37%). In a small sample this season, the curve is in the zone 63% of the time.

He’s better with the pitch than without it but how much better is tough to figure out. Luke Weaver’s NFBC ADP ended at 108th overall. Other starters around his value were Jake Arrieta, Jose Berrios, and Kyle Hendricks. I’d probably value him similarly to the pitchers in the 65-75 ADP range (Jose Quintana, Dallas Keuchel, and James Paxton) for now. Owners can look to possibly buy at pre-season prices and get a small value bump.