Polymarket Promo Code TSN: Deposit $10, Get $20 Bonus for MLB Predictions (August 18) originally appeared on The Sporting News. Add The Sporting News as a Preferred Source by clicking here.
New customers can unlock a $20 bonus after making an initial deposit of just $10 with the Polymarket promo code TSN. Register here to start making trades on a variety of MLB outcomes.
This is the perfect bankroll boost to help us handicap the board for today's exciting matchups—like the New York Yankees taking on the Baltimore Orioles or the Seattle Mariners facing the Milwaukee Brewers—as well as any other MLB game scheduled for this week.
Polymarket Promo Code TSN for MLB Trades
| Polymarket Promo Code | TSN |
|---|---|
| New User Offer | $20 Bonus |
| Terms and Conditions | 18+ and Present in the US |
| Date Last Verified | August 18, 2026 |
As an aspiring strategist, you know there is nothing better than building your bankroll with extra funds. By claiming this offer, new customers can secure a $20 bonus to use across today's action-packed MLB schedule. Whether you want to back the St. Louis Cardinals at Great American Ball Park or take a shot on the San Diego Padres as they visit Citi Field, this welcome promotion gives us the extra capital needed to chase bigger payouts with confidence.
Unlocking your bonus is a completely straightforward process. The $20 bonus funds will hit your account after you successfully make an initial deposit and execute a first-time deposit of at least $10.
MLB Moneylines and Probabilities for Tuesday
| Matchup | Moneyline | Probability |
|---|---|---|
| NYY @ BAL | NYY -113 / BAL +101 | NYY 51.6% / BAL 48.4% |
| STL @ CIN | STL -117 / CIN +105 | STL 52.5% / CIN 47.5% |
| SD @ NYM | SD -113 / NYM +102 | SD 51.7% / NYM 48.3% |
| ARI @ BOS | ARI +150 / BOS -166 | ARI 39.1% / BOS 60.9% |
| SEA @ MIL | SEA +137 / MIL -151 | SEA 41.2% / MIL 58.8% |
I am always looking for the smartest ways to leverage our bankroll. If you want to use some of your funds today, placing a standard $20 trade on the board's heaviest favorite—the Boston Red Sox (-166)—would yield a steady profit of $12.05 if they pull through. On the flip side, putting that same $20 on the day's biggest underdog, the Arizona Diamondbacks (+150), returns a solid $30.00 profit if we can catch them pulling off an upset.
When we're handicapping these matchups, diving into the numbers helps us uncover real value. Looking at the ARI @ BOS clash, Boston justifies being the heavy chalk. The Red Sox pitching staff boasts a strong 3.50 team ERA compared to Arizona's 4.13 mark, and their lineup holds a clear edge with a .724 OPS over the Diamondbacks' .712.
Meanwhile, the AL East showdown of NYY @ BAL presents a fascinating contrast for our betting cards. The Orioles hold a marginal advantage at the plate (.720 OPS vs. .716 OPS), but New York counters with a dominant rotation carrying a stellar 3.26 team ERA—nearly a full run better than Baltimore's 4.24 ERA. That glaring pitching advantage is exactly why the Yankees are the smart slight road favorites tonight.
How to Register Using the Polymarket Promo Code
- Create an Account: Begin the registration process here by entering your standard personal information.
- Verify Your Identity: Provide a valid proof of identification to secure and verify your new account.
- Enter the Promo Code: During the sign-up process, make sure to enter the Polymarket promo code TSN.
- Make a Deposit: To officially activate the offer, complete a deposit of $10.
Once your initial deposit clears, your account will be fully loaded with your bonus, and we'll be ready to attack today's MLB action with a serious edge.