Fantasy Baseball: 3 Things We Learned in Week 5

Baseball fans love their stats. We devour them, dissect them, and build our fantasy rosters around them. Each week of the 2021 baseball season, we will be gifted with another statistical sample size of pitches, plate appearances, and playing time. Knowing it often takes hundreds or even thousands of pitches or batted-ball events for trends to normalize, how should fantasy managers adjust to the ebbs and flows of weekly player performance?

Each week during this season, this piece will look at trends that have emerged over the past week and determine if it is signal or noise moving forward. What is prescriptive in helping build winning fantasy teams and what can be ignored as small sample size noise? Hopefully, we can make sense of what has just happened to help us make smarter roster and free agent budget decisions.

Let's take a look at some of the data from the fifth scoring period of the fantasy baseball season.

Franmil Reyes Continues to Crush

It seems that the birth of his new child is the only thing that can stop Franmil Reyes from crushing baseballs these days. While he is on a three-day hiatus, it's time to appreciate the power with which he is hitting this season, and maybe throw a couple of trade offers toward his manager while he spends time out of the lineup.

Traditionally thought of as a three true outcomes type of player (home run, walk, or strikeout), Reyes has shifted more towards a two-outcome player this season: smash or strikeout. And when he smashes, it is a sight to behold.

Reyes' name is littered throughout the Statcast hitting leaderboards. He is now top-10 in hard-hit percentage (57.9%), average exit velocity (94 MPH), barrels per batted ball event (22.8%), barrels per plate appearance (14.3%), and just outside the top 10 in expected slugging percentage (.663).

The walk and strikeout combination is the ugly side of the coin, however. His strikeout percentage is a career-high 33% so far this year, and the walk rate is a career low 3.3%. Those things should normalize somewhat going forward, but for now, Reyes is in the 10th percentile for avoiding strikeouts and the 7th percentile for drawing walks. His chase percentage of bad pitches is the highest of his career (31.7%), but if he can just regress back to his career 8% walk rate, it would do amazing things for his overall profile.

But the most impressive thing Reyes is doing with his mammoth power this year is learning to spray the ball all over the field. Here is his hit chart, courtesy of Baseball Savant.

This is not someone who is defaulting to just a "see ball, pull ball" approach but rather taking the right pitches and learning where to put them. Even though his chase percentage might need work, the fact that his first pitch swing percentage is a career-low (29.7%) shows that he is learning to wait for the right pitch. When he gets ahold of it, watch out.

Now he has the baby narrative on top of all of this, so a 20-homer month is likely incoming.

Jose Urquidy: New Spin Doctor

Baseball Savant defines active spin as the amount of spin that contributes to a pitch's movement. More movement on a pitch is usually a good thing, so more active spin usually equals more movement, which translates to a harder pitch to hit for batters.

If that's an equation we can rely on, then we may need to prepare ourselves for a full-on Jose Urquidy breakout.

The Houston Astros starter throws four pitches primarily: a four-seam fastball, changeup, slider, and curve. Of those four pitches, he throws the fastball and changeup almost 72% of the time. It's no surprise that these are his go-to pitches because both have evolved to possess elite active spin rates that are making them some of the best pitches in the game.

Urquidy's four-seam fastball has 99.4% active spin, meaning the spin contributes to almost 100% of the movement. That ranks ninth among all pitchers (starters and relievers) and is followed closely by his changeup which has a 97.9 active spin rate -- another elite number.

FanGraphs rates Urquidy's fastball as the 16th-most valuable among all pitchers this season, which explains why even with a relatively low K/9 rate of 7.2%, he can generate a 3.70 ERA. His ERA also doesn't appear to be in line for any course correction. It lines up perfectly with his expected ERA (3.70) and expected fielding independent pitching (3.85).

If you drafted Urquidy in the later rounds of your draft, just sit back and enjoy the ride. He is also still available in 36% of Yahoo leagues, so run to your waiver wire and see if you pluck him up.

Add or Trade for Alex Kirilloff

Alex Kirilloff (42% rostered in Yahoo leagues) - I saw a very interesting tweet from Todd Zola over the weekend that made me think about the way teams handle their stud prospects and how much leash to give them during their first exposure to Major League pitching.

As someone who entered this fantasy season with several shares of Andrew Vaughn (especially after my shares of Eloy Jimenez went in the tank) and no exposure to Alex Kirilloff, these are two I will be closely watching. But it's clear what Zola is saying above. While Vaughn is being yanked in and out of the lineup, the Minnesota Twins have put Kirilloff in a position to show off what he's got since day one.

And he is finally starting to do it.

After going hitless his first five games (going 0-for-14), Kirilloff now has a hit in six straight and is batting .292 (7-for-24) with 4 home runs, 10 RBI, and 5 runs in that span. He still needs to learn to take a walk (only one all season), but he has four minor league seasons with an on-base percentage above .340, so I am sure that will come.

Entering the year as MLB Pipeline's 21st-rated prospect (and second on the Twins), expectations were sky-high this year after Kirilloff took the unusual step of debuting during the MLB playoffs last year. And it's clear the Twins, who have aspirations of a long playoff run, were going to let Kirilloff have a chance to figure everything out and make adjustments at the big league level. He has now hit in the fourth or fifth spot of the lineup in 8 of 11 games.

What the Twins organization must be seeing under the hood is a player whose barrel rate is an astounding 29.6% in his limited time (the league leader among qualified players is 23.2%) and whose average exit velocity of 96.2 MPH on 27 batted balls would rank fourth among all hitters if it qualified.

His growing pains might not be completely over, but this is a player who is figuring out how to hit big league pitching quickly, and the team shows no signs of letting him see the bench.