Will Cain says James Harden has to become more of a team player when Chris Paul returns from injury for the Rockets. (1:52)

Houston Rockets star James Harden is on a historic pace, with 21 straight games scoring at least 30 points, including a career-high 61 against the New York Knicks on Wednesday night.

Defenders aren't the only ones having a hard time keeping up.

Six hours before game time, the Westgate Las Vegas SuperBook has moved Harden's over/under for points scored in Friday night's game against the Toronto Raptors to an astronomical 42.5, setting the record for highest over/under point total it has ever posted.

Harden finished with 35 points in the Rockets' 121-119 win.

The line had opened at 41.5, which tied the previous high -- for Harden's Monday night game against the Philadelphia 76ers. Harden went under, scoring 37 points in three quarters but sat out the fourth quarter as the Rockets fell 121-93.

"It's a reaction to what we're seeing through the betting window," Jeff Sherman, vice president of risk management and oddsmaking at the SuperBook, told ESPN. "If Harden goes on a string of games where he hits 50 a few times in a row, we may have to increase it more because in the low 40s, we're not going to get much under money on it. We did see two-way action at 41.5 on Monday."

Caesars Palace opened a prop on whether Harden would score 60 or more points in a game this season last Thursday, with the yes favored at -130 and immediately took a $500 limit bet on the "yes." It cashed less than a week later.

"Harden had only scored 60 points once in his career, so it's not an easy feat even for him," Caesars Palace senior oddmaker Matt Lindeman said. "We thought it would be a good prop where squares would want to bet the yes, but with Chris Paul coming back we thought Harden's usage would go down. We really just needed to get through Wednesday night's game and we'd be safe. Sure enough, the Knicks found a way."

Harden's historic run hasn't affected handle on individual Rockets games, both bookmakers said. It has impacted the MVP market, though, where Harden was 8-1 a month ago at the SuperBook, +150 two weeks ago and now is a -500 favorite. Giannis Antetokounmpo has the second-best odds at +350, with LeBron James, Stephen Curry and Joel Embiid the next-best odds at 20-1.

"The European market has Harden at an even shorter price than we do," Sherman said. "I've been trying to stay aggressive and bump up LeBron and Davis, but it really looks like a two-man race. We're not seeing money on Giannis."

Lindeman said they didn't have plans to put the 60-point prop back up at Caesars, or another one with a higher total.

"I think at this point you're a glutton for punishment to doubt Harden again."