Two starting pitchers and Houston Astros shortstop Jeremy Pena are featured in my top MLB prop pick recommendations on Thursday.
Today’s MLB props narrative: Pena and the Astros are slumping, but I like them to get on track against a pitcher who just dominated them. As for the starters, I like Sonny Gray‘s matchup and believe context is important when viewing Sean Manaea‘s outs line.
Check out my favourite MLB prop bets for Aug. 21.
MLB prop bets
Best bet: Manaea over 16.5 outs (-122)
The New York Mets are just at the beginning of a gruelling stretch that sees them play 16 consecutive days in a row.
Unless they’re shuffling arms back and forth between the minors, they’re going to need their starters to step up to prevent overtaxing the bullpen.
David Peterson did that against the Washington Nationals on Tuesday, though Kodai Senga laboured through five innings last night.
Peterson, a southpaw like Manaea, took advantage of his plus matchup: 8 IP, 1 R, 10 Ks.
Manaea is set up for a good showing, and I believe he can stay out longer than what we’ve seen from him since making his season debut mid-July.
- The Nationals have a well-below-average offence vs. lefties, per wRC+, and they’ve struggled at the dish in the second half.
- Washington ranks 25th in wRC+, 27th in on-base percentage and 27th in home runs.
They aren’t putting runners on and aren’t hitting for pop. And the forecast is calling for a decent amount of wind blowing in, creating favourable pitching conditions.
Manaea has been roughed up three starts in a row and has only cleared this line once. But he has delivered strong K numbers (10.41 K/9) and isn’t issuing free passes.
Key stat: Manaea was excellent in five July starts, pitching to a 2.08 ERA with a 5.50 K/BB rate.
Best MLB picks
Gray over 6.5 Ks (+140): I see big value here.
- Gray has a well-above-average 26.9% K rate, ranking in the 81st percentile (per Baseball Savant).
- He has cleared this line in three straight and gotten to at least six strikeouts in more than half his starts.
- The last three right-handed starters to face the Rays all cleared this number (Justin Verlander, Logan Webb, Cam Schlittler).
- Tampa has the third-highest K rate in the second half, a sub-.300 OBP and ranks last in wRC+.
Gray can pile up Ks in short outings. But this looks like one where he can also provide length, giving him more strikeout opportunities.
Pena over 0.5 runs (+105): Baltimore Orioles rookie Brandon Young is coming off the game of his life, taking a perfect game into the eighth inning against the very same Astros he’ll see tonight.
Young’s final line: 8 IP, 1 H, 0 R, 0 BB, 6 K.
He lowered his ERA a full run, but enters tonight’s start at Camden Yards in Baltimore with a mark of 5.68. At home, he’s sitting on an 8.10 ERA through six starts.
The Astros have been dreadful, scoring two runs over their last four games. In their last eight, they’ve been shut out four times and scored more than two runs in a game twice.
Pena, the club’s leadoff hitter, hasn’t provided much since missing all of July, but has stellar season-long splits: .310/.368/.479.
Despite Young’s brilliance last start and Houston’s team-wide slump, this is a great spot for the Astros to right the ship.
And at plus money, I’ll take the table setter in a friendly hitting environment (No. 4 for offence and No. 2 for homers, per Baseball Savant’s park factors).
Baltimore’s bullpen has a 4.93 ERA in the second half (25th in MLB).
MLB prop picks made at 11:05 a.m. ET on 08/21/2025.
Chris joined NorthStar Gaming from Covers.com where he was a publishing editor and wrote betting content. Before that, he was the sports editor at VICE Canada, worked for theScore and covered the Blue Jays for MLB.com. In addition to filling out the lineup card each day for the editorial team, Chris writes frequently himself, primarily on the NBA and MLB.