To play the penthouse bet line my favorite way I write down a 1. If I win I circle it and cross off 2 lost bets to the left of it if there are any. If I lose I write another 1 to the right of it.
Here's the line 111222333444555 etc...
Option: You can't drop to a lower bet level unless you win 2 times in a row.
So if we are here 1 1 1 2 2 2 3 3 and we win on the 2nd 3 we circle it and cross off the 1st 3 but we don't cross off the 3rd 2. We bet 3 again and if we win here we can cross of the 2nd and 3rd 2 because we won 2 in a row. Our next bet would then be the 2nd 2 and we continue.
This adds an element of aggressiveness to our line, but not too much.
This will cause us to win about 30% more units than the original method of move 1 to the right on a loss and cross off 2 numbers to the left on a win.
GLC