Best NBA Prop Bets Today (Predictions for Stephon Castle, Kevin Durant, Trae Young)

Breaking down the best prop bets for the NBA action on Sunday, Dec. 21, including a pick for Stephon Castle.

San Antonio Spurs guard Stephon Castle is a great prop target on Sunday. / Brett Davis-Imagn Images

What's a better way to bet than kicking off a Sunday with some NBA player prop action? 

There are a bunch of intriguing matchups in the NBA on Sunday, starting with a 3:30 p.m. EST tip between the Chicago Bulls and Atlanta Hawks and ending with the Houston Rockets on the road against the Sacramento Kings. 

Here’s a quick look at the full slate of games:

• Chicago Bulls vs. Atlanta Hawks
• Toronto Raptors vs. Brooklyn Nets
• Miami Heat vs. New York Knicks
• San Antonio Spurs vs. Washington Wizards
• Milwaukee Bucks vs. Minnesota Timberwolves
• Houston Rockets vs. Sacramento Kings

There are a couple of star players out on Sunday, as Tyler Herro won’t suit up for Miami and Giannis Antetokounmpo is sidelined for the Bucks. 

However, superstars like Victor Wembanyama, Jalen Brunson, Anthony Edwards, Trae Young and more will be in action.

I’ve narrowed things down to a few props for Sunday’s slate, so let’s break down each of these picks – and their latest odds – on Dec. 21. 

Best NBA Prop Bets for Sunday, Dec. 21

Odds via DraftKings Sportsbook.

Norman Powell OVER 24.5 Points (-108)

Tyler Herro is out of the lineup for the Heat on Sunday, which sets up well for Norman Powell against the Knicks.

Powell has torched New York this season, scoring 29, 38 and 19 points in his three games against Mike Brown’s club. The Heat star should operate as the No. 1 scoring option on offense, especially if Andrew Wiggins (questionable) ends up sitting out this game as well.

Powell is averaging 24.1 points per game while shooting 48.7 percent from the field and 41.1 percent from beyond the arc this season. He’s taking a career-high 16.3 shots per game, which gives him a tremendous floor in a Miami offense that loves to push the pace on offense. 

I’ll back Powell to clear this number for the third time in four meetings with New York this season. 

Trae Young 8+ Assists (-157)

Earlier today, I shared in my NBA Best Bets column – Peter’s Points – why I’m betting on Young in his second game back from an MCL injury: 

After missing over a month with an MCL sprain, Trae Young returned to action against the Charlotte Hornets on Thursday, putting up eight points, 10 assists and a steal in just over 20 minutes of action.

There’s a good chance Young remains on a minutes limit on Sunday, but the star guard has proven that he can still dish out a ton of assists in limited action. Young has averaged double-digit dimes for three seasons in a row and at least 8.1 assists per game in every season in his NBA career.

Now, he takes on a Chicago team that is just 23rd in the NBA in opponent assists per game and 27th in opponent points per game.

In limited action this season, Young is averaging 8.2 assists on 14.3 potential assists per game. He has three games with at least 10 dimes, and I think he’s a steal at this number against a terrible Chicago defense. 

Stephon Castle OVER 6.5 Assists (-122)

Spurs rising star guard Stephon Castle has been a terrific playmaker as of late, dishing out 12 assists in the NBA Cup Championship against the Knicks and seven or more dimes in three straight games.

He’s coming off a seven-assist game on Thursday against this Washington team, and the Wizards rank 29th in the NBA in opponent assists and opponent points per game this season.

The former lottery pick is averaging 6.9 assists per game on 12.3 potential assists in the 2025-26 season, so he should have plenty of chances to hit this number on Sunday night.

Washington’s defense has been extremely porous this season, and Castle needed just 25:08 to clear this prop on Thursday and 23:55 to clear it on Friday against Atlanta. 

Bobby Portis OVER 12.5 Points (-123)

With Giannis Antetokounmpo still out of the lineup for the Bucks, I’m buying veteran big man Bobby Portis on Sunday against the Timberwolves. 

Portis is averaging 12.3 points per game this season, and he’s been extremely efficient, shooting 49.3 percent from the field and 47.7 percent from beyond the arc. 

In the games that Giannis has missed (11), Portis is averaging 16.7 points, 6.7 rebounds and 1.3 assists per game, clearing 12.5 points in seven of those matchups. He has 27, 10 and 24 points in his last three games.

Even though the Timberwolves are a strong defensive team, I think this line is a little low with Portis clearly seeing an expanded role. He’s averaging 10.0 shots per game for the season, but that jumps to 12.5 per game when Giannis is out. 

Kevin Durant OVER 4.5 Rebounds (-156)

On Saturday night, Kevin Durant had 31 points, six rebounds and five assists in a huge win over the Denver Nuggets, and I’m buying him as a prop target on the second night of a back-to-back against the Sacramento Kings.

The Kings rank just 25th in the NBA in opponent rebounds per game and dead last in rebounding percentage this season. That sets up well for KD and the rest of the Rockets, especially with Durant’s rebounds prop set relatively low at 4.5

KD is averaging 4.8 rebounds per game this season, but he’s cleared 4.5 boards in 13 of 23 games this season, including each of his last three. Overall, the superstar forward is averaging 7.7 rebound chances per game in the 2025-26 campaign.

I think this is a dream matchup for Houston on the boards, and Durant should find his way to his season average or better on Sunday night.

---

Odds refresh periodically and are subject to change.

If you or someone you know has a gambling problem and wants help, call 1-800-GAMBLER.

Find Peter Dewey's NBA betting record here (futures included). You can also follow my daily plays on  BetStamp here.

Claim the latest DraftKings promo code offer today. Sign up and win your first $5 bet to get $200 in bonus bets instantly.