Buyer Beware? Hot Starts and Fantasy Baseball Waiver Wire Analysis (Week 21)

The fantasy baseball playoffs are in about three weeks in many leagues and standard trade deadlines have come and gone. That means each pickup off the waiver wire for the rest of the season is that much more crucial to the future success of our fantasy baseball teams. When there are six months to get things right, a lot of room for error exists. When fantasy baseball is down to just six weeks? Grabbing the wrong guys at the end of a hot streak can be detrimental.

Players like Zach Neto, Josh Bell, and Brandon Lowe are exceptionally hot right now, but will it last? These are some of the hottest pickups of the week. Just because these players are at the head of the class for this week's waiver wire doesn't mean the production will continue through August and September. Diving deep into their performances should tell a better story. That's the goal of this piece today.

Below are four players who are widely recommended as waiver-wire options across the fantasy baseball industry this weekend and deserve a closer look. It's not to say that these are not strong options for your teams considering your league's context, but each deserves a more critical eye based on their recent performance.

Colton Cowser, OF - Baltimore Orioles

Before Jackson Holliday came back to the big leagues and set the world on fire, it was Colton Cowser who was the only rookie prospect to be pulling their weight on the Orioles. On the season, Cowser has been very good with a .250/.332/.458 line including 17 home runs and seven steals. At the end of games on Friday night, Cowser (-260) was the favorite to win AL Rookie of the Year. And while his numbers all year have been excellent, his case for the rookie award has been significantly propped up by his elite last month. In the last 30 days, Cowser is hitting .330/.394/.534 with five home runs and two steals.

We can't take away those numbers at all, but it's safe to predict that they will come crashing down soon. Cowser's batting average on balls in play (BABIP) during that time is .421, the 10th-highest number in the league. His strikeout rate has actually gone up to over 27% so he is swinging and missing a lot in the second half. Cowser has also hit 47% of his batted balls on the ground in that time, so the power and the line-drive ability seem to be quite fluky based on the numbers under the hood.

Jake Burger, 3B - Miami Marlins

It was another day and another home run for Jake Burger on Friday. He hit his fifth home run of the last seven days and is on some kind of massive power hot streak right now. He has 20 home runs despite missing more than 20 games due to injury this season. When Burger has played, he has looked just like the dominant hitter who blasted 34 home runs in 2023. Miami chose not to trade Burger at the deadline, so the 28-year-old third baseman is going to get all the playing time he can with the Miami Marlins down the stretch. The only issue, however, is that Burger is doing some outlandish things with his batted balls that are highly unrepeatable.

Jake Burger has reached 10 homers since the second half began -- tied with three others for #MLB lead.

His .677 slugging percentage entering tonight ranked third among players with at least 50 plate appearances.

Jonah Bride goes B2B. #Marlins pic.twitter.com/yq670ldunB

— Christina De Nicola (@CDeNicola13) August 9, 2024

First, Burger is hitting almost 50% fly balls. That's not a crazy number, although he is only at 40% for his career. But what's even more insane is what's happening with those fly balls when they are in the air. Over the last 30 days, exactly one-third of Burger's fly balls have turned into home runs. The league average during that time was just 12.8%, so Burger is almost three times that number. I have no doubts some power will continue, and he will keep hitting balls in the air, but to keep hitting home runs at this rate seems unrealistic.

Gavin Lux, 2B - Los Angeles Dodgers

Fantasy managers have seemingly been waiting years for Gavin Lux to break out, and it seems he is finally doing it in the second half of 2024. Over the last 30 days, Lux is demolishing the ball to the tune of .385/.461/.662. Only five players have a higher OBP and 13 players have a higher slugging percentage, and they are names like Judge, Soto, Witt, and Guerrero. Lux has four home runs and 15 RBI of his own in that time, but luck has truly been on his side the last few weeks, and that means there could be some slowing down soon.

Gavin Lux last 20 games:

.400-BA/1.171-OPS 🔥

I'm glad they kept giving him reps and time to readjust after missing *all of last year* with a torn ACL pic.twitter.com/WD5DKqMUnt

— Fuzzy (@fuzzyfromyt) August 6, 2024

In the last four weeks, only Xavier Edwards among qualified batters has a higher BABIP than Gavin Lux's (.488). For his career, Lux has a .312 number, almost exactly in line with league averages. His strikeout rate is up and his walk rate is down in 2024, so this amazing streak he is on is likely generated by a lot of luck. Luck has a tendency to come crashing down in baseball at any given moment.

Colin Rea, SP - Milwaukee Brewers

Colin Rea deserves a tremendous amount of credit for his excellent performance as a starter after so many seasons missed with injury and time toiling away in the minor leagues. His 3.35 ERA across 122 innings is one of the main reasons the Brewers are in position to win another division title this season. Over the past 30 days, it's hard to find a pitcher who has been better. Rea has a 1.57 ERA with over 11 strikeouts per nine innings and well under one home run per nine as well. However, one statistic sticks out that could send his stats in another direction if the luck starts heading the other way.

Colin Rea, K'ing the Side in the 3rd. pic.twitter.com/BSxOli3xS9

— Rob Friedman (@PitchingNinja) August 7, 2024

In the last month, only two pitchers in all of baseball have a higher left-on-base percentage (LOB%) than Rea's 94.1%. That means 94% of the batters who reach base against Rea do not score. This sounds impressive, and it truly is, but some might say that number is unsustainable. The league average of LOB% is about 72% this season, and Rea is at 71.6% for his career. Even in this, his best season ever, his seasonal number is just over 79%, so expecting 94% of baserunners to continue to be stranded would be quite a stretch. Rea is still one of the best waiver wire finds of the year, but his expected ERA (4.75) shows his performance could take a turn soon.

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