[tessarji]

Here's my ideas on it. I'd also search the archives about the straddle for more delightful discussion.

A mandatory straddle is obviously 0 EV in itself, since everyone bears the same disadvantage on their UTG hand. The effect on the game is determined by how well players adjust.

There are now three blinds, small, big, and double. Obviously avoid paying the double sized blind whenever possible. Posting is a far superior way to enter the game.
If you aren't required to make up the straddle if you miss the blinds, I would try to be absent from the table during blinds whenever possible.

Outside the blinds, a somewhat tighter pre-flop strategy is optimal. You are guaranteed a medium sized pot on any hand you open raise with. Stealing the blinds is obviously much better, but will never occur with the straddler getting 6:1 pot odds at least. Your hand selection should be somewhat skewed towards high card values, and away from 'implied odds' hands. It is critical that you make it 3 bets with pretty much any hand you enter with to drive out the BB. You should remove limping from your pre-flop play.

Although the game is tighter pre-flop, it is much more aggressive. Three and four bets preflop are fairly common, as the best hands fight over the dead money from the blinds. Postflop, it plays just like holdem with a rather larger starting pot (less raising, less slowplaying, since there are usually fewer players to attack and better drawing odds).

Look for hands with good showdown value preflop. You will be going to the river often. Aces to AJo or A9s are great candidates. Low pockets are much worse, even if the straddler misses the flop he will often have correct odds to peel off a card.

Pick your straddle buddy carefully. If players are playing optimally (tight when not in blinds) then many hands will be 2 or 3 way with the raiser in position. Try to get people on your left who release quickly if they miss the flop. This will often be a mistake.

If someone else raises before you, you can cold call in position a little more liberally with a potentially dominated hand like AJo or KJs. This is because the game is proportionally 'smaller' after the flop so you will generally be punished less. A better idea might be to four bet with the best of these hands.

Obviously, you want to lose as little as possible in the blinds. You'll almost always play preflop in the straddle. The BB has it particularly hard with a lot of money invested, and a potential re-raiser after them. Don't get involved in the BB when it is two bets to you without some serious cards, at least JJ/AQ/AJs. Four bet with all these hands.

When you are in the straddle, you'll find yourself playing a lot of mediocre hands against the preflop raiser. Since you will usually be out of position and the pot will be large, get used to a lot of check-raising. In general you should probably not raise much preflop out of the straddle, you'll usually be better off leading or check-raising the flop.

This rule does definitely make more of a two-card game, with less relevant poker strategy post-flop.

Anyone agree or disagree with my take?