MLB Barometer: Risers & Fallers

Congratulations to all of you who are still reading fantasy baseball articles with fantasy football draft season in full swing. I assume all of you esteemed readers are in the playoffs or fighting for the top spot in your roto leagues. For those of you who aren't, it's time to start thinking about where to take Yordan Alvarez next season (a topic which will be discussed in a few paragraphs).

If you're still jockeying for position in a roto league, it's time to start thinking hard about risk. If you're holding on to lead heading into the final few weeks of a season, it's wise to decrease your risk profile. If you're still trying to make up ground, you have to look at making some risky moves. Even if a transaction's expected value makes your team worse, it could be worth considering, as there's typically far more to gain from moving from second to first than there is to lose from falling from second to third.

That means that someone chasing down the leader has plenty of reason to target a newly promoted rookie, while someone holding onto a lead won't want to risk that player having a tough time adjusting to the big leagues. The chasers also may have to take a chance on some shaky outings for their borderline starters, while the leader would benefit from minimizing the chances of a blowup. The leader will still want to make sure they have enough innings down the stretch to keep their counting stats up, but they'll still want to consider a ratio-stabilizing non-closing reliever. To the extent that streakiness is a legitimate (if immeasurable) quality of players, those players who are inherently more streaky should appeal to owners who still need to make up ground, as those owners need a few lucky breaks to win their leagues.

RISERS

J.D. Martinez, OF, Red Sox: It might not have been enough to get his team back in the wild card race, but Martinez was in vintage form in August, posting a 1.242 OPS. The veteran's hot streak really dates to late July. Through July 19, Martinez owned a .284/.359/.507 slash line, excellent numbers for most players but not up to expectations from the player who had an NFBC ADP of 5.9. It appeared as though aging was kicking in for the slugger in his age-31 season. Since July 20, however, he's been incredible, hitting .396/.471/.785. He's improved his hard-hit rate from 44.6 to 53.0 percent over that stretch while increasing his pull rate from 38.4 to 47.8 percent. Martinez's 1.233 OPS during his hot streak may be a bit much for him to sustain down the stretch, but he's recorded an OPS higher than 1.000 in each of the previous two seasons, so he may not fall by all that much.

Nicholas Castellanos, OF, Cubs: Castellanos featured in this column at the start of August, as his change in circumstances following his deadline-day trade to the Cubs seemed to foreshadow good things for the rest of his season. That prediction certainly seems to be accurate so far. Whether he's single-handedly taken down analytics is up for (a rather stupid) debate, but the Cubs certainly won't be complaining about what he's achieved. In the month since joining his new team, he's posted an excellent .336/.373/.689 slash line and doubled his season homer total with 11 bombs. The 27-year-old's batted-ball profile doesn't look all that different for his new team, so some regression is certainly in order, but his improvement in home park should continue to help see more of his hard-hit flyballs leave the yard and the improvement in the lineup surrounding him should continue to prop up his run and RBI totals.

Nick Anderson, RP, Rays: Has anyone ever pointed out that the Rays know how to get the best out of their players? Given their reputation, it should come as no surprise that Anderson has improved on his 3.92 ERA in 43.2 innings with the Marlins, but it surely would have been overly optimistic for forecast his 0.77 ERA, 0.43 WHIP, 0.0 percent walk rate or his incredible 56.4 percent strikeout rate in his 11.2 innings for his new team. It's hard for a non-closing reliever to have fantasy relevance outside of very deep leagues, but if anyone is to do it, it would be a player who strikes out more than half of the batters faced while allowing barely any baserunners. The Rays don't appear to be looking to bump Emilio Pagan from his closer role, though he has allowed four runs over his last four appearances. With Anderson dominating to the extent that he has for his new team, he's worth an add for strikeouts and ratio stability in a wide variety of leagues, with at least an outside chance of adding a bonus save or two down the stretch.

Yu Darvish, SP Cubs: Darvish featured in this column in mid-July, as his strong strikeout and walk rates over his last five starts at the time forecast an improvement on his 4.72 ERA. That improvement has indeed come, as he's recorded a 3.28 ERA over the eight starts since that article while posting an excellent 33.2 percent strikeout rate and a near-perfect 1.0 percent walk rate. Homers are still a problem — he's had one start where he allowed three and another where he allowed four in August — but those tend to be far less stable than strikeouts and walks, so there's plenty of reason to buy in down the stretch. The veteran was scratched from his start Sunday due to forearm tightness, which does provide some reason to worry, but he's only expected to miss one start, and he's reportedly been battling the issue all month with seemingly very little effect on his performance.

Lucas Giolito, SP, White Sox: Giolito stumbled into the All-Star break, posting a 7.11 ERA and a 14.1 percent walk rate over his final four starts of the first half, casting some doubt on the sustainability of his excellent start. The brief rest seemed to be exactly what he needed, however, as he's been on a roll since the break, recording a 3.53 ERA in 10 starts while striking out 35.0 percent of batters and walking just 6.6 percent. Prior to allowing four runs and striking out seven Monday against the Braves, he'd recorded six consecutive quality starts while average double-digit strikeouts. Giolito's second-half showing is remarkable compared to what he'd shown prior to this season, but it's in line with his numbers from earlier in the year, so there's plenty of reason to believe he can sustain a similar performance down the stretch.

Yordan Alvarez, OF, Astros: Alvarez's 1.241 OPS through his first 12 career games earned him a very early feature in this column in late June. It wasn't particularly novel to suggest that he could hardly sustain quite that level of performance, but the 22-year-old is at the stage of his career where simply not falling off much is enough to make him a riser. He's done just that, as he followed up his 1.139 OPS in June with a 1.045 OPS in July and a 1.095 mark in August. It's clear at this point that Alvarez is for real. His 180 wRC+ on the season is tied with Mike Trout for the lead among all hitters with at least 250 plate appearances. His draft stock will be interesting to follow this offseason. For comparison, Juan Soto finished with an NFBC ADP of 33.3 after posting a 146 wRC+ and 22 homers in 116 games as a rookie. Alvarez has a significantly better overall batting line and already has just 21 homers, though he's only played in 65 career games. Still, it wouldn't be surprising to see Alvarez beat Soto's mark by a handful of picks.

FALLERS

Caleb Smith, SP, Marlins: Smith got off to a strong start to the season, posting a 3.35 ERA through his first 18 starts of the season while striking out 30.2 percent of batters, showing noticeable growth from his 4.19 ERA and 27.0 percent strikeout rate last season. He's endured a rough time over his last five outings, though, striking out just 21.2 percent of batters and allowing seven homers en route to a 8.06 ERA, raising his season ERA to 4.30. Smith will always be a home run risk, as he simply can't keep the ball on the ground; his 27.8 percent groundball rate ranks last among all pitchers with at least 100 innings this season. The easiest way to avoid giving up home runs is to never let hitters make contact in the first place. Smith will be a shaky fantasy option down the stretch unless he gets back to missing bats.

Daniel Vogelbach, 1B, Mariners: Vogelbach started the season surprisingly hot, hitting .310/.462/.732 through the end of April. It was easy to predict that he'd fall off to a certain extent, though he'd maintained a solid .238/.375/.505 batting line through the All-Star break. He's really slowed down lately, though, hitting just .130/.256/.273 in August. His strikeout rate jumped to 30.0 percent over the course of the month while his hard-hit rate plunged to 22.0 percent after being higher than 45.0 percent in three of the first four months of the season. Prior to homering Sunday, he'd hit just two homers in his last 22 games. It's certainly possible Vogelbach can crawl out of the slump and approach his early season performance down the stretch, but he's shown very little in his big-league career outside of this April, so expectations should be muted.

Didi Gregorius, SS, Yankees: It was natural to assume that Gregorius would take some time to recover from the Tommy John surgery that caused him to miss the first two months and change of the season. He actually hit quite well initially, however, posting an .805 OPS in his first 20 games and a respectable .764 mark in his first 50 contests. He's struggled since mid-August, however, hitting just .174/.240/.413 over his last 13 games. It's unclear if the downward trend is a result of his surgically repaired elbow tiring or if it's just a simple slump. In either case, the Yankees can afford to sit him more frequently down the stretch due to the expanded September rosters, so Gregorius might not be a particularly interesting option in September.

Nick Senzel, OF, Reds: The MLB season can be a long one for rookies. Senzel didn't exactly storm out of the gate in his first season at the big-league level, but he hit quite respectably, posting a 108 wRC+ in May, a 98 wRC+ in June and a 126 wRC+ in July. That number cratered to 36 in August, however, the result of a .184/.238/.296 slash line. His 26.9 percent strikeout rate and 4.6 percent walk rate were each his worst figures in any month this season, as was his 13.0 percent line-drive rate. The Reds have little reason not to let him work through the slump, as he's one of their more important pieces for the future and they've fallen out of the wild card race, but his floor is low and his ceiling is only moderately high the rest of the way.