The question came up in the early days of The Chip Board. Gene remembered that the dealer at the 21 table in the early days called a player's natural a 'snapper'. For some reason, that came to be applied by chip collectors to a $2.50 chip as $5 blackjack was becoming common about that time as dollar and 2-dollar tables became scarce.

Some expressed the opinion that 'snapper' came from the sound made when a player "snapped his cards down" on the table to indicate he had a blackjack. This was before shoes became common and players were still allowed to handle the cards dealt to them.

These days, many chip collectors who started out collecting $2.50 chips began adding to their collection the other denominations that have a 50c in the number (like $7.50 chips for a $15 hand and $12.50 for a $25 hand). I did the same.

Other collectors who branched out into foreign casinos started calling every chip denominated in a foreign currency that had the number 250 in it a snapper. Thus you will see some snapper collections with 250, 2500, and even 25000 denominations depending on how cheap the local currency was.