"Football remains king, even when the Colts get off to a slow start as they did in September," said Nicole Russo, an analyst for PlayIndiana.com. "A busy schedule of Indiana, Notre Dame, and Purdue football certainly helped boost interest, too. The bottom line, though, is that the state's industry continues to grow and mature and that will likely lead to even stronger months ahead as baseball's postseason starts and the NBA returns."

Online and retail sportsbooks generated a record $355.4 million in bets in September, edging the previous record of $348.2 million set in January, according to official reporting released Tuesday. September's handle was up 71.3% from $207.5 million in September 2020 and up 64.8% from $215.6 million in August, as bettors increased the pace of betting to $11.8 million per day over the 30 days of September. That is up from $6.9 million per day in September 2020 and $7 million per day in August.

Gross gaming revenue reached $33.3 million, topping the previous record of $31.7 million set in January. September's revenue was up 196.4% from $11.2 million in September 2020 and up 99.4% from $16.7 million in August. Taxable revenue landed at $33.9 million in September, yielding $3.3 million in state taxes.

Through the year's first nine months, Indiana's sportsbooks have combined to generate $2.4 billion in wagering and $206.6 million in gross gaming revenue, already easily surpassing the $136.4 million in revenue on $1.8 billion wagered in all of 2020.

"The bar has been set much higher for Indiana's sports betting market, and could double the wagering from last year," said Eric Ramsey, an analyst for the PlayUSA.com Network, which includes PlayIndiana.com. "Indiana remains one of the five largest sports betting markets in the country, and the growth is showing few signs of letting up at this point. Sportsbooks should approach $4 billion in wagers for the year."

Football attracted $148.6 million in wagering in September, which is a dramatic gain from the $48.4 million wagered on football in September 2020. Interest in the Colts remained strong even as they started 0-3, and sportsbooks even got a boost with the surprising Cincinnati Bengals.

Baseball was a popular bet, too, drawing $52.9 million in wagering in September. That is up from $30.5 million in September 2020.

"Sportsbooks have made a hard push to attract customers this fall," Ramsey said. "We're just starting to see the fruits of those promotions, but September's wagering makes it clear that those efforts are already working to expand the overall customer base."

Online betting produced $320.1 million in wagers, 90.1% of September's handle. DraftKings led online operators with a $130.4 million handle in September, producing $7.2 million in gross receipts. FanDuel was again No. 2 in the state with $77.2 million in online wagering and a state-best $10.6 million in gross receipts.

Meanwhile, operators used football as an opportunity to gain market share. That includes high-profile partnership deals between the Colts and Caesars and WynnBET.

"Operators use the increased interest in betting that inevitably comes with football season to increase brand awareness and eventually carve out market share," Russo said. "With so many brands operating in Indiana, the competition for deals with other high-profile brands like the Colts are fierce, but they can help boost visibility."

Retail sportsbooks took in $35.3 million in wagering in September, up from $20.4 million in August. Hollywood Lawrenceburg, nearest to Cincinnati and one of the highest-volume retail sportsbooks in the U.S., led retail books in Indiana with $11.5 million in wagers.