Let me try and explain better.
Say for example (here i'm using the dealer...but same thing is happening to players at the same time) dealer deals himself 5 cards that total up to 21. The next round of betting begins but the old cards are not wiped from the table. Dealer again deal himself 5 cards that total up to 21..but "10" cards are really showing totaling up to 42! If that expalnation don't get it thru ask Canaboids becuase he was there when it happened also....like 4 times during our time there.
Boo2U out

-edit-
Using the example above, you lost the 1st round with say a 13, the next round you are almost certain of winning because dealer would be showing 42 and there is NO way for you to break his 42 without yourself busting! A 21 would only total up to a 34 ( 13 + 21) for you! ANY split the second time around is a certain big win for you!