Stacks are the backbone of cashing daily fantasy baseball lineups. Correlation drives upside, creating the potential to place high or even win GPPs when your selected stacks explode offensively.

This column will do the digging and the dirty work to determine which stacks are worth rostering each day. Scoring upside will fuel the stacks that get the nod. Sometimes that will lead to chalky selections, but contrarian stacks will get their fair share of love too.

In addition to utilizing the touted daily stacks in handbuilt lineups, numberFire premium members can throw these highlighted stacks into an optimized lineup using our DFS Sharpstack tool. Our hitting heat map tool is also available to premium members looking for more stacking options. It provides valuable info such as implied total, park factors, and stats for identifying the quality of the opposing pitcher.

Let's take a look at the top stacks on today's main slate.

Toronto Blue Jays

The Toronto Blue Jays are the club that is lucky enough to draw Matt Harvey for what's likely to be his latest meltdown. According to FanGraphs, in 381 and 1/3 innings pitched since 2017, Harvey's responsible for a 6.37 ERA, 4.87 skill-interactive ERA (SIERA), and 1.82 homers per nine innings allowed. In 15 starts and 62 and 1/3 innings this year, he has a 7.80 ERA, 4.78 SIERA, and 1.44 homers per nine innings allowed. In five starts stretched across a paltry 16 and 2/3 innings over the last 30 days, Harvey's been tattooed for an 11.88 ERA, 5.00 SIERA, and 2.16 homers per nine innings allowed.

Remarkably, Harvey's play is sliding from an already terrible level to an unbelievably inept level. Tonight, he faces the fourth-best offense against righties this year. The Blue Jays own the fourth-highest weighted runs created plus (110 wRC+) and third-highest isolated power (.189 ISO) against right-handed pitchers. Impressive marks for Toronto's righty-heavy lineup, and Harvey won't present much opposition in same-sided matchups. He's been ambushed for a .561 slugging percentage and .413 weighted on-base average (wOBA) by the 168 righties who've faced him this season.

Any mention of stacking the Blue Jays has to include highlighting the exemplary work of Vladimir Guerrero Jr. ($4,800). This year he's played at an otherworldly level, amassing a .437 on-base percentage, .375 ISO, and 210 wRC+. Whether you're stacking the Blue Jays or rolling with another stack, I can't advise strongly enough to use Vladito.

Anyone in the Jays' lineup has merit for usage with Harvey throwing batting practice these days. However, the other player I'll explicitly call out is Marcus Semien ($3,700). He has a .347 on-base percentage, .256 ISO, and 136 wRC+ against right-handed pitchers this year.

New York Yankees

Dare I say stacking the New York Yankees has a similar ceiling to the aforementioned Blue Jays? I do! The wheels have fallen off for Martin Perez. He's lasted only 21 innings in his last five starts, getting roughed up to the tune of a 6.00 ERA, 5.29 SIERA, and 2.14 homers per nine innings in that time.

The Yankees haven't lived up to their Bronx Bombers moniker, for the most part, this year. That's not the case for Gary Sanchez ($3,100) and Aaron Judge ($3,900), though. The former has a .339 ISO and 143 wRC+ against southpaws this season. The latter has been even better, recording a .224 ISO and 166 wRC+ in the split.

My two preferred options to join Sanchez and Judge in a full, four-person stack are Luke Voit ($2,500) and Giancarlo Stanton ($3,600). Voit's reached base in all three games since being reinstated from the injured list, and he's homered in two of those contests. Stanton's come up short against lefties this year. However, he's long been one of the game's elite lefty-killers, owning a .365 on-base percentage, .277 ISO, and 148 wRC+ against them since 2018.

Houston Astros

Tonight's GPP winning scores are likely to be bananas. Why's that? Because the Houston Astros have their own mouth-watering matchup, and they're only my third-favorite stack tonight. Houston's locked in. They've scored double-digit runs in three of their last four games and plated seven or more runs in five of their last six. They're the top offense against righties this year with a 125 wRC+, and they've steamrolled the opposition over the last 30 days, with a 146 wRC+ in that span.

Houston is awesome, yet I feel as if I'm burying the lede. They're facing Wily Peralta. Peralta wasn't in the bigs last year, and he was used as a reliever in 2018 and 2019. He last started before this year in 2017, making eight starts and 11 relief appearances. This campaign, he's made one relief appearance and one start. The Los Angeles Angels jumped him for five runs on seven hits, two homers, two walks, and two strikeouts in five innings in his only start in 2021. In 138 and 1/3 innings pitched since 2017, he's in Harvey territory with a 6.18 ERA, 5.11 SIERA, and 1.50 homers per nine innings with the benefit of pitching most of those innings from the bullpen.

Everyone in Houston's lineup is on the table as a stacking option. Peralta's coughed up a .320 wOBA to righties and a .363 wOBA to lefties for his career. With that in mind, I'll tout Michael Brantley ($3,800), Yordan Alvarez ($4,100), Kyle Tucker ($3,400), and Abraham Toro ($2,500). All four will hold the platoon advantage against Peralta.

Joshua Shepardson is not a FanDuel employee. In addition to providing DFS gameplay advice, Joshua Shepardson also participates in DFS contests on FanDuel using his personal account, username bchad50. While the strategies and player selections recommended in his articles are his/her personal views, he/she may deploy different strategies and player selections when entering contests with his/her personal account. The views expressed in his/her articles are the author’s alone and do not necessarily reflect the views of FanDuel.