MLB DFS Picks Today: Perfect Lineup For July 21

Dave Loughran and Josh Engleman are both back behind the desk for a 13-game Tuesday, and the build they land on argues against Loughran's own scouting report from a season ago: Luis Castillo (SEA) at $7,600, a discount arm in Matthew Liberatore (STL) at $6,700, and a Colorado Rockies stack anchored by Hunter Goodman (COL) and Mickey Moniak (COL). None of that looked obvious at first pass. The Rockies build tested at a modest 32% simulated ROI on the first run through the Stokastic Sims, and it took one specific swap to change the grade completely. Hold that number, because the payoff comes at the end.

Luis Castillo — one of the featured players on today's slate.

In Summary

• SP1: Luis Castillo (SEA) at $7,600 vs. the Cincinnati Reds, a matchup-and-park case despite Loughran having "railed against Castillo all season long."
• SP2: Matthew Liberatore (STL) at $6,700 vs. the Los Angeles Angels, the salary-saver that made the final lineup over the pricier Ranger Suarez (BOS) lean.
• The Stack: the Colorado Rockies (COL) at home against Washington National Michael Lorenzen, anchored by Hunter Goodman (COL) and Mickey Moniak (COL).
• The Payoff: one lineup tweak took the Stokastic single-lineup Sim from a 32% simulated ROI to a 61.2% simulated ROI and a 38% cash rate.
• Offer: 20% off Stokastic MLB with promo code PERFECT20 — the last week the show is running this discount before it scales back for football season.

Watch The Video

Watch Dave Loughran and Josh Engleman build the full lineup live in the Sims: Watch on YouTube.

Luis Castillo (SEA): Betting The Matchup Over The Track Record

Every build starts with a decision, and this one starts with Loughran talking himself into a pitcher he has spent all season fading. "I've railed against Castillo all season long," he says on the show. "He's just not the same pitcher." Yet Castillo ($7,600) is the SP1 call tonight against the Cincinnati Reds, and the case is built entirely on matchup and park, not a sudden return to form.

It starts with the strikeout market. Only two pitchers on the entire slate carry a strikeout prop above 5.5, and neither clears 6.5. One of them is Cincinnati's Chase Burns (CIN), Castillo's own opponent tonight. The other is Castillo himself. That is the same juiced Reds-at-Mariners environment that produced a 27-DraftKings-point outing from George Kirby (SEA) a night earlier — six scoreless innings and six strikeouts on just 80 pitches, one of the only real pitching scores on a night where almost every pitcher didn't go more than four or five innings. Castillo draws the identical matchup tonight, and while Loughran is careful to say he's no Kirby, the underlying numbers travel: Cincinnati is dead last in the league in wRC+ against right-handers at 88, and the Reds' active roster carries the third-highest strikeout rate against right-handed pitching in baseball at over 24%.

Then there's the park. Instead of hitting inside Great American Ball Park, one of the sport's better home-run environments, the Reds have to travel to T-Mobile Park, which grades as the single worst hitters' park in baseball. Castillo shows it in the Stokastic data too: he's second in top-two-pitcher probability and projected fantasy points at his price point, third in top value among all pitchers on the slate, and only the tenth-highest-priced arm despite that ranking. Cincinnati's team total sits at 3.8, tied for the lowest of any team on the 13-game board. "It's a matchups play. It's a data play. It's a props play. It's a park play," Loughran says. "It is not a Luis Castillo is elite again play. Let's not get it twisted here." When the price, the matchup and the park all point the same direction, that's the trigger to pull, even against your own season-long read.

Matthew Liberatore (STL) Vs. Ranger Suarez (BOS): The Lean That Lost To The Play

SP2 is where the two-pitcher framework matters, because Loughran names a favorite that never actually makes the built lineup. His preferred payup option is Ranger Suarez (BOS) at $9,200 against the Baltimore Orioles, who carry the highest strikeout rate against left-handers in baseball this season at 27.4%. Suarez is walking back from the injured list and hasn't pitched since July 5, which tempers the excitement, but Loughran still calls him "my favorite option at the top" if he's willing to pay up. That's a lean, not a fired play — Suarez never enters the actual build.

The pitcher that does is Matthew Liberatore (STL) at $6,700, and the case is almost entirely about what the savings buy elsewhere. Liberatore faces an Angels lineup that Loughran flags for a 25%-plus strikeout rate against lefties in its own right, and he's cheap relative to the field: fourth in value score in the Stokastic data and eighth in top-two-pitcher probability among all arms on the slate. The Angels aren't hitting for power the way they did a year ago — 15th in ISO, 15th in weighted on-base average, and 15th in wRC+ against left-handed pitching. The one real risk is the long ball. Liberatore is allowing 1.67 home runs per nine this season, and a $6,700 arm giving one up is the kind of outcome that can sink a build fast. But the discount is real: $2,300 cheaper than Suarez, funding the rest of the roster.

Pitcher	Salary	Opponent	Role
Luis Castillo (SEA)	$7,600	vs. Cincinnati Reds	SP1, the matchup-and-park lock
Matthew Liberatore (STL)	$6,700	vs. Los Angeles Angels	SP2, the salary-saver that made the build
Ranger Suarez (BOS)	$9,200	vs. Baltimore Orioles	The payup lean that stayed on the bench

The Suarez row is the one worth sitting with. He's the pitcher Loughran says he'd rather have, and the show still didn't roster him, because the cheaper arm frees up exactly the salary the Rockies stack needs. That's the trade-off every DFS build eventually makes: the best pitcher on paper isn't always the pitcher that wins the lineup.

The Stack: Colorado Rockies At Home Against Michael Lorenzen

That saved salary goes straight into Colorado. Engleman takes over the stack duties and goes to the Rockies against Washington National Michael Lorenzen, and the case starts with the Stokastic tools before it gets to the matchup: Colorado is second in top-stack probability, first in stack score, and second in ownership on the day, which Engleman is upfront about. "We're not going to the chalk chalk chalk, but we are the chalk for sure," he says. "That's what happens when you're playing in Coors."

The matchup backs it up. Colorado isn't a great offense in the aggregate, sitting 21st in wRC+ against right-handers, but the power profile is real: third in ISO against right-handed pitching this season, fifth if you narrow it to the active roster. Lorenzen, meanwhile, isn't missing bats and is giving up hard, powerful contact at a rate that makes him a target regardless of who's in the box. Hunter Goodman (COL) at $6,100 is the most chalk piece in the build, a natural catcher-slot lock around 13% owned, and Mickey Moniak (COL) at $5,700 is right behind him. Everything after those two drops under $5,000, which is what lets the build spread out.

Rockies Piece	Salary	Role in the build
Hunter Goodman (COL)	$6,100	Catcher lock, ~13% owned, easiest home-run buy on the roster
Mickey Moniak (COL)	$5,700	Second bat locked alongside Goodman
TJ Rumfield (COL)	$4,500	First base, sub-$5K salary relief
Kyle Karros (COL)	$3,700	Third base, sub-$5K salary relief
Troy Johnston (COL)	—	Added in the outfield during the Sim tweak below

Goodman's row tells the story of the whole stack: he's the one piece the field is already on, and everything built around him is there specifically because it isn't.

Worked Example: One Swap Doubles The Sim ROI

Here's the build Loughran and Engleman actually ran in the Stokastic single-lineup Sim. Locks: Castillo and Liberatore at pitcher, then Goodman, Rumfield, Karros, and Moniak at the bats, with roughly $4,000 per remaining position to fill a shortstop and two outfield spots. Clicking "complete this lineup" filled those three slots automatically off the projections, landing on Arizona's Geraldo Perdomo at short and Max Kepler in the outfield as a two-man Diamondbacks stack, plus a lone Washington National bat as a correlation piece with the Rockies' own game. That first build left $700 unused on the table.

Running the simulation against a full contest-sized player pool graded it at a 32% simulated ROI, a 0.1% chance to win, and a 35% cash rate — solid, but not the number either host was expecting from a build this deliberate. So they made two swaps. Troy Johnston (COL) came in for a second Rockies outfielder, Perdomo stayed at shortstop, and second base flipped from the auto-filled pick to Arizona's Ketel Marte, with Baltimore's Tyler O'Neill taking the final outfield spot. The new build used $100 more of the salary cap.

Re-running the Sim on the tweaked roster returned a 61.2% simulated ROI, a 2% chance to win, and a 38% cash rate — nearly double the projected return on the same core pitchers and the same Rockies anchor, from two position swaps and $600 in freed-up salary. That's the number this whole build was building toward: the Castillo bet and the Liberatore discount only mattered because they left enough room for the Sim to find that second version of the roster. "Those are the little tweaks you can do in the single-lineup Sim at stokastic.com," Loughran says. "Those tweaks will get you perfection."

Build and stress-test your own version with the MLB DFS projections, ownership and stacks in the DataHub, the same tools behind every read in this build.

Lock in the discount. The Sims, projections and single-lineup optimizer above are how the Perfect Lineup crew grades every build before it locks. This is also the last week the show is running its current discount before it scales back into football season — get 20% off any Stokastic MLB package, weekly, monthly or all-access, core or max, with code PERFECT20: Start building with Stokastic MLB Sims.

FAQ

What is the Perfect Lineup show? It's Stokastic's daily MLB DFS build show, run by Dave Loughran and Josh Engleman, where Loughran sets the pitchers, Engleman sets the stack, and the two hand the build to the Stokastic single-lineup Sim to grade and refine it live.

Why play Luis Castillo after a season of fading him? Because the matchup and the park both point the same direction: a Cincinnati lineup that's dead last in wRC+ against right-handers, moved out of a hitter's park and into the worst home-run venue in baseball. Loughran is explicit that this isn't a bet on Castillo returning to form, just a spot where the price, matchup and park all line up.

Who is the top stack for MLB DFS today? The Perfect Lineup build stacks the Colorado Rockies at home against Washington's Michael Lorenzen, anchored by Hunter Goodman and Mickey Moniak, with the rest of the salary spread across sub-$5,000 pieces.

How do I build these lineups myself? Use the Stokastic MLB DFS Sims and projections and the single-lineup optimizer, and grab 20% off with code PERFECT20 before the discount tapers for football season.

The Bottom Line

Every piece of tonight's build only works in relation to the others: Castillo's park-and-matchup case funds a pitcher spot Loughran didn't trust on reputation alone, Liberatore's discount over the pricier Suarez lean frees the salary the Rockies stack needs, and that stack only reaches its ceiling once the Sim gets a second look at the roster. The jump from a 32% to a 61.2% simulated ROI on essentially the same core is the real lesson: the first lineup the tool hands you is a starting point, not the answer. Build your own version in the Stokastic MLB DFS Sims & projections, and grab 20% off Stokastic MLB with code PERFECT20 at stokastic.com while the show is still running it.