When you sit down at a BJ table and you give your players card to the bit boss they take the card and scam the card to get your information. Normally they hand it back to you and watch a few hands to see the amount you are playing. Sometimes you see them again. Other times you may not. What do you do when you are done playing. Do just get up and leave or ask for the person again? Thanks
If you've been playing for awhile, betting $25 and up, you may want to ask the floorperson what they rated you at. Otherwise you leave and they will input it. Hopefully scan it, although there may be some scams involved. And no, it's not an exact science. Tip the dealer.
If you never change your bet from hand to hand, you can be almost sure that they're going to get you right. If you're playing at $25 or above and leave, the dealer will let the Pit Boss know you're going and he'll log you out. If you've widely varied your best, it's good to check with the pit boss to see what he got you for, but it's sometimes hard at blackjack because they aren't always near you. It's easier at craps.
If you're playing in the HL room, odds are they're tracking your play much more closely and accurately - though it's still a good idea to check at the end of your session if you're concerned you're not getting rated accurately. But on the main floor - where they're usually busier & much more likely to be only jotting down your first few bets, or only every so often - the conventional wisdom is to bet a little bigger your first few bets, or whenever you notice the pit critters are watching you play - that way, if you're betting in a range of [say] $25-$100/hand and concerned if you start off at $25 that they'll rate your entire session at $25, if you start out at [say] $50 for the first few hands, and bump it up to $50 or $75 whenever they walk by, you'll probably have a better chance of being rated at closer to your true average - because [let's face it] out on the main floor they've got a lot more tables & players to track, so you want to make the best impression when you know they are watching.