Yeah. The mirror peekers use special cards that have the ten/ace values printed sideways just above the index. That way the ten/ace cards will show up in the mirror but any other card will not. The electronic peekers use a little dark spot on the corners to know whether the card is a ten/ace. You can often see some of these marks if you buy cards from the casino gift shop.
I was under the impression these were licensed. Turning Stone supposedly didn't want to pay a $5 a table per shift fee for these,so they handchecked.
After losing hundreds of thousands to anyone that could figure out what a warped card meant,they relented.
A casino near me used to use the No Peek 21 with the red light for BJ, but they now have the mirrors. I wonder why they dumped the light device?
And why not just use the mirror thing in the first place? It's probably cheaper and seems like it would be more durable.
I've noticed a couple different styles for the mirror BJ checker. The most common seems to be having the A index on all four corners. 10's have the index raised higher so they can be seen when checking under an A.
Another style is having the A raised higher than the other indexes, and having a special symbol on 10's on the corners without index numbers.
the place i worked at switched from the lights to the mirrors after 3 years because at times the lights wouldnt work right so you would check, finish the hand, flip over your cards and have BJ, which killed sometimes 10+ cards on a full table taht should have still been in the shoe. they occasionaly get stuff stuck in them giving false readings at times, and if a wire gets unplugged, they will show green or red lights at all times, its great as a player for a dealer to check, flip a supposed blackjack and end up with 15/16 i love seeing that malfunction
The one I've seen the most are ones where the cards are only marked on two corners, but different corners depending on the value. If you number the corner of a card 1, 2, 3, 4 (so that 1 & 3 are opposite corners), they number all the non-tens on corners 1 and 3, and the tens on 2 and 4.
When a dealer checks for BJ under a ten, he inserts corner 1/3 into the mirror so that either an A or a number shows. If an ace is up, he rotates the cards 90 degrees and puts corner 2/4 into the mirror so that either a blank or a 10 shows.
Some cards have a bar on the A to differentiate it from a 4. In the good old days, you could often tell if dealer had T4 because he'd look twice when checking for blackjack.