When betting at the sports book and say I want to bet on a bunch of games on a parlay ticket. How many can I actually bet on?? Example...I want to bet on 15 total games on a certain saturday, NBA AND NCAA basketball games? Could I do that?? Is there a max of games I can bet??
Most "cards" have limits stated, as others have said.
Consider making "off the board" parlay bets though instead. The only advantage to cards is that if the lines move a little you can still get the original line ( this is much more prevalent in football where the cards are available days ahead of the games ). But in hoops they are only available a little in advance. And even in FB they take games off the card that move much or cross any key numbers anyway. Cards offer much worse ODDS than off-the-board parlays typically. But you get the current spread "at the time you make the bet" on off the board parlays. Most players that works fine for anyway.
Most books only allow up-to 8 teams in an OTB parlay though, so 15-teams is a bit much.
Also consider breaking those 15 games up into more smaller parlays though. IMO, the sweet-spot for parlays is 3 teamers. There is one place in Vegas, and a couple online, that offer 6.5-1, aka 7.5 for 1, odds on 3 teamers OTB. Notice that 1/2 pt FB card pictured above offers 6.5 for 1 on 3 teamers(5.5-1) which is really awful. The "7.5 for 1"(6.5-1) equates to less vig than straight -110 bets.
Your chances of hitting the parlay grow proportionally as you add teams. So it is twice as hard to hit a 3 teamer as a 2 teamer, and twice as hard to hit a 4-teamer as a 3-teamer. Thus when you get into the 12 or 15 team depths you are really not being very realistic. Throwing away $2 or $3 on a big parlay card is whatever, but if you are a +EV handicapper, 2 or 3 teamers can compound winnings just as if you are a poor handicapper they WILL COMPOUND losses relatively. So only winners should consider them, and they can compound winnings for them.
I will be seeking out that one LV book that offers 6.5-1 3 teamers to play hoops at on my next trip. They also offer 13.5-5 on 2 teamers ( while most others offer 13-5 on 2-teamers OTB ).
I have played at two online books that not only had 6.5-1 on 3 teamers, but both had -105 specials on FB on Friday evenings - both ended those offers eventually. Combining the offers you actually got > 7-1 on 3 teamers ( meaning better than 0 vig bets ). Don't tell any "parlay bigots" that they could get bets effectively better than +100 though! LOL No hoops deals that good, only FB. You could literally play round-robin 3-teamers for profit at those books, IOW. I can still get 6.5-1, and 14-5 on 2-teamers online at one book.