Last week's 5 fantasy surprises: Should managers buy Matt Chapman's summer surge?

The real-life MLB trade deadline provides fantasy managers with one final chance to re-evaluate their teams. Most fantasy leagues hold their trade deadlines around the same time, meaning early August marks the final chance for teams to make a big splash before the season ends.

Now is the time to crunch the numbers and figure out which players are expendable, and which players are bound for an excellent second half. Thankfully, we're here to help with that.

Ranks are based on standard Yahoo fantasy leagues

Matt Chapman, Toronto Blue Jays 3B

Fantasy rank over the last seven days: 2

Season-long fantasy rank: 81

Big things were expected of Matt Chapman his first year in Toronto. Finally freed from the Oakland Athletics' cavernous ballpark, there was hope Chapman would turn in the best offensive season of his career.

Chapman's been productive thus far, hitting .249/.326/.482 with 20 home runs, but hasn't fully put things together yet. That may have changed in July. He hit .325/.396/.699 during the month, fueling his recent fantasy surge.

He's bound to regress at some point, but there were some positive developments in his July numbers that could point to a big second half. Chapman pulled 55 percent of his batted balls in July, a big jump over his previous months. Given how often he puts the ball in the air, this is a significant development in Toronto, where it's much easier to hit a home run compared to Oakland. He also hit the ball harder in July. It's possible that regresses when this hot streak ends, but it's still encouraging to see.

Chapman's approach remains somewhat flawed. He strikes out a lot and his over-reliance on fly balls will never lead to a .290 batting average. But if he's finally taking advantage of his new park, he won't be a negative in batting average. If Chapman can hit .260 with close to 40 home runs, he would be in the running for fantasy MVP considering his low price tag on draft day.

Brady Singer, Kansas City Royals SP

Fantasy rank over the last seven days: 23

Season-long fantasy rank: 238

My colleague Scott Pianowski believes Kansas City Royals pitcher Brady Singer deserves more attention and I concur. Singer has taken a massive step forward over his last five starts, posting a 2.05 ERA with 42 strikeouts in 30 2/3 innings.

Singer was already on his way to a solid season thanks to his improved control. Singer cut his walk rate from 9.0 percent — below average for a starter — to 6.1 percent this season. In doing so, he's turned one of his biggest weaknesses into a strength.

There's also evidence something has changed for Singer over his last five starts. His sinker has taken another step forward. His sinker whiff rate was up in July, per BrooksBaseball.net, and he's changed how he uses it against righties. Singer previously used the sinker to get ahead in counts and then relied on the slider to pick up strikeouts against right-handers. He reversed that in July. Singer is more confident using the slider early in the count and then using his sinker with two strikes.

It's possible this is small sample luck, but the effectiveness of the sinker combined with the new approach suggests Singer worked to make this change. The Royals don't offer a ton of fantasy value generally, so Singer could be a bright spot on an otherwise disappointing second-half club.

Kyle Tucker, Houston Astros OF

Fantasy rank over the last seven days: 584

Season-long fantasy rank: 49

Kyle Tucker has simultaneously been a useful fantasy asset and a disappointing one. After hitting .294 last season, Tucker is hitting .240 in 2022. His season-long fantasy value is the result of him hitting 19 home runs and stealing a career-high 16 bases.

At the plate, Tucker hasn't lived up to expectations. The home runs are nice, but Tucker is running a .448 slugging percentage. He's slugged above .500 in each of the past three seasons.

There are two things holding Tucker back: his inability to hit changeups and his launch angle. The changeup has previously been an issue for Tucker, but he made an adjustment last year and started mashing against opposing changeups. Tucker hit .311 with a .608 slugging percentage against offspeed pitches last season. Those figures have dropped to a .132 average and a .226 slugging percentage.

When Tucker is making contact, he's getting under the ball. Usually, this is a good thing, but Tucker has taken it to the extreme. His average launch angle is eight percent higher than the MLB average. It's led to Tucker popping up more balls instead of driving them into the gaps, which could explain his lower slugging percentage.

Predicting whether Tucker will get back on track is difficult. On the one hand, he's shown the ability to crush changeups and his launch angle issues look like an outlier. On the other hand, he's had half a season to make those adjustments and it hasn't happened yet. Tucker is still going to be a valuable fantasy contributor down the stretch, but any chance of him living up to his top-20 upside depends on whether he can recapture his line-drive stroke and clobber changeups again.

Taijuan Walker, New York Mets SP

Fantasy rank over the last seven days: 496

Season-long fantasy rank: 104

Taijuan Walker has been a fantasy revelation for those who refused to give up on his talent. He's posted a 2.79 ERA over 103 1/3 innings after struggling with the New York Mets last season.

Walker has done so with a different approach. He doubled his split-finger usage, taking it from 14.2 percent to 28.7 percent. That's been a great decision. The pitch has been dominant. Batters are hitting just .177 against it and it gets whiffs at a 28.3 percent clip. When batters are making contact, they are beating the pitch into the ground, which helps support Walker's low 7.3 percent home run-per-fly ball rate and better ground-ball rate.

The approach does have drawbacks. Walker's strikeout rate has dropped and his average fastball velocity dipped below 94 mph after last year's increase. That tradeoff hurts, though it might be by design. Walker has cut his walk rate, which is possibly due to focusing on command over velocity.

In many cases, Walker's negatives would be worrisome and an indication regression was incoming. But the emergence of the splitter and Walker's change in approach offer an explanation for his strikeout regression.

Betting on Walker to keep this up depends on whether you believe his split finger has truly become one of the best pitches in baseball. The early signs are promising.

Merrill Kelly, Arizona Diamondbacks SP

Fantasy rank over the last seven days: 83

Season-long fantasy rank: 77

If you had the foresight to draft Merrill Kelly in March, congratulations on being related to Merrill Kelly. The 33-year-old right-hander didn't have much value after posting a 4.44 ERA last season.

If you were wise enough to pick him up early, your fantasy team has benefited in a major way. Kelly has a 2.87 ERA over 125 1/3 innings. If he keeps this up, he'll receive some down-ballot Cy Young votes. That won't matter for your fantasy team, but it highlights the shocking nature of his turnaround.

That's all fine and good, but fantasy managers are wondering whether Kelly's resurgence can continue in the second half. On the surface, his stats look similar. Kelly's strikeout rate hasn't jumped, he hasn't cut his walk rate dramatically and his batted ball data remains unchanged.

The main thing fueling Kelly's success is his home run rate. Kelly has a 5.2 percent home run-per-fly ball rate in 2022. Over his career, he's allowed home runs on 11.7 percent of his fly balls. Kelly is allowing more ground balls this season, but not at an extreme rate, suggesting he's bound to regress once his home run rate normalizes.

If that happens, there's evidence Kelly can still be an effective pitcher. He's reworked his repertoire this season and is relying more on his changeup and cutter as secondary offerings, both of which have been excellent. In addition to that, Kelly's velocity is up. That has really helped his four-seam fastball. Batters hit .311 against the pitch in 2021, when it averaged 91.7 mph. The pitch is averaging 92.6 mph this season, and batters are hitting .239 against it.

Fantasy managers can deal Kelly if they fear it's all going to come crashing down. But if opposing managers are wary of Kelly's numbers – and they probably are — that's not the worst outcome. Kelly might still provide value in the second half, even if he starts to give up more home runs.