Stacking is an integral part of daily fantasy baseball. Correlation drives upside, giving your lineups a slate-winning ceiling when your stacks explode.

This piece will do the digging and the dirty work each day to determine which stacks are worth rostering on FanDuel's main slate. While we want upside, we also need to factor in game theory, especially in a sport as random as baseball.

The MLB DFS heat map at numberFire is a quick way to get a feel for the overall slate and which offenses are in a good spot. You can also check out our daily fantasy baseball projections -- which are powered by numberFire -- to identify the slate's best bats.

Let's look at the top stacks for today's main slate.

MLB DFS Stacks

New York Yankees

Implied Total: 5.72 | Opposing Pitcher: Dan Altavilla

The New York Yankees are set up to score a boatload of runs tonight -- per usual. The fifth-highest scoring offense in baseball gets a matchup with right-hander Dan Altavilla, a 31-year-old making his first career start and who, prior to this season, had pitched 1.1 innings of Major League ball dating back through 2021.

It's hard to envision the Kansas City Royals allowing Altavilla to pitch too deeply into this one, meaning we should see them turn to their bullpen sooner rather than later. According to Baseball-Reference's Wins Above Average metric the Royals' relievers rank 10th-worst in the Majors, while according to FanGraphs' SIERA metric they rank second-worst with a combined 4.38 SIERA mark.

This is a pretty obvious setup for success, so Yankees stacks will require a pretty hefty portion of your allotted salary for today's slate. Aaron Judge ($5,000) and Juan Soto ($4,500) are projected for the most (17.9) and second-most (16.0) FanDuel points on today's slate and understandably have the highest and second-highest salaries. They're arguably the two best hitters in baseball right now, and they have a choice matchup -- if you want to add them to your lineups, you'll need to plan accordingly.

Anthony Volpe ($3,400) offers a slightly more accessible way to get exposure to the Yankees in your lineups. The emerging star has seemingly cemented himself as the team's leadoff batter and is thriving in that role, with a .758 OPS and an impressive 48 runs scored on the year (tied for 10th). He's been slumping in June so far, but this seems like a perfect get-right spot for him.

Considering that this is such a good spot for all Yankees hitters, it could be worth dabbling in some of their other veterans currently batting fourth through seventh. Giancarlo Stanton ($3,000) has mashed 16 homers this year -- including one last night -- but has been pretty cold in June. He's easy to roster relative to the top of New York's lineup and has the second-shortest odds to hit a home run (+285) in this one, making him a decent option tonight.

Alex Verdugo ($3,000) is projected for a solid 11.8 FanDuel points, while each of Anthony Rizzo, DJ LeMahieu, and Gleyber Torres can be rostered for under $3,000. Rizzo in particular could be a callout here -- he's batting just .048 over the last week (22 plate appearances) but has only struck out once in that span. He's putting balls in play but not getting to base (his .242 BABIP is the second-lowest of his career in a full season). Variance could swing back his way in this one.

Kansas City Royals

Implied Total: 4.78 | Opposing Pitcher: Cody Poteet

The flip side of the same matchup doesn't look too shabby, either. The Kansas City Royals will get a matchup with Yankees right-hander Cody Poteet, who has gotten strong results in his first three starts despite some average behind-the-scenes numbers.

To that effect, as good as Poteet's 1.72 ERA and 0.96 WHIP look on the stats sheet, they might not accurately reflect his performance to date. The 29-year-old has a 4.35 FIP, a 5.47 expected ERA, and a 4.16 SIERA backing up his sterling ERA and WHIP. Batters facing him have just a .209 BABIP, and he's only striking out 18.0% of those he faces. He could be queued up for a less fortunate night tonight against the strong side of the Royals' platoon.

Bobby Witt Jr. ($4,500) is the only Royals batter who truly matches the upside that Judge and Soto carry for the Yankees. The star is projected for 13.2 FanDuel points in this contest and has a .929 OPS on the year.

Maikel Garcia ($3,300) bats leadoff and is projected for 12.0 FanDuel points in this one. He's been having a rough June at the plate but benefits from having a bonafide star like Witt Jr. behind him in the lineup.

Salvador Perez ($3,200) is having his best season in years with 10 home runs and a .853 OPS on the season. He has already drawn more walks (21) in under half a season this year than he did in either of his last two full campaigns, and his 15 doubles this year are just shy of the 23 and 21 doubles he notched in 2022 and 2022, respectively. His +350 odds to hit a home run are the shortest of any Royals batter tonight.

Vinnie Pasquantino ($3,000) is the last bankable Royals hitter for tonight. The third-year first baseman started the year off slow but has rebounded lately and is rocking a .945 OPS over the last two weeks. He's even put up the first two triples of his career in that span and is continuing to draw his characteristically high number of walks while keeping strikeouts to a minimum -- he has three of each over the last week. In New York's home run-friendly park, he could grab his eighth dinger of the season off of Poteet tonight.

The bulk of Kansas City's offensive production should come from those hitters tonight, but Nelson Velazquez ($3,000) has been hitting homers lately and could be worth a look tonight. The young slugger has 3 home runs over the last two weeks but is batting for a meager .188 average in that span. He's a home run or bust play at this stage, but given Poteet's lower strikeout rate, he could fare well tonight.

New York Mets

Implied Total: 3.99 | Opposing Pitcher: Braxton Garrett

The New York Mets are not having a great year, but they have been great against left-handed pitchers -- according to FanGraphs' wRC+ metric, their offense is the fifth-best in baseball against lefties. That positions them for a solid series against the Miami Marlins' lefty-heavy rotation and for a great night tonight against Braxton Garrett.

When Garrett is on, he's capable of producing some incredible outings -- like in his complete game shutout against the Arizona Diamondbacks last month. But when his stuff isn't working, there's a potential for disaster. That's why he's still carrying a 5.81 ERA despite that recent shutout. And given how well the Mets have produced against left-handers on the year, I'm leaning towards tonight's tilt being closer to the disaster side of things than to the shoutout side.

The top of the Mets' lineup should all be in play here. Francisco Lindor ($3,600) has had a pretty slow start to the year, but over his career, he has historically been a slow starter -- he has a career .797 OPS in the first half of seasons versus a .842 OPS in the second half. He seems to be heating up a bit more recently and has been mashing lefties this season with a .508 SLG, so he could be a good play here.

Pete Alonso ($3,500) may not be producing the Aaron Judge-esque numbers the Mets need from him to become a winning team, but he's still having a solid enough season with a team-high four homers against left-handers on the year. The projections at numberFire have him notching 11.4 FanDuel points in this one.

The Mets' two veterans could be the team's best offerings for tonight's slate. Starling Marte ($3,300) and J.D. Martinez ($3,000) have been on fire lately -- and especially against left-handers. Marte is batting .333 with a .483 SLG against them on the year, while Martinez has hit the ground running since his delayed start with 2 homers and .326 average off of lefties.

Mark Vientos has been shockingly hot for the Mets this year with a team-high .968 OPS through his opening 84 plate appearances. He's cooled off over the last week, but with a $2,400 salary, it's not hard to fit him into Mets stacks tonight.

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The above author is a FanDuel employee and is not eligible to compete in public daily fantasy contests or place sports betting wagers on FanDuel. The advice provided by the author does not necessarily represent the views of FanDuel. Taking the author's advice will not guarantee a successful outcome. You should use your own judgment when participating in daily fantasy contests or placing sports wagers.