If you play SSS with double stack it is no more call SSS it is call MSS

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Middle stack strategy lol
SSS is like a do or die strategy as it involves a lot of all in preflop so you double up or you lose your BI.By doubling up u will probably get more than 30 BB.
Why the 25 BB leave room rule?
Not always will they follow your raise most of the time they will fold your raise.Often you will get 5 BB by raising without no one calling your raise.
IF you raise 4 time in four room and get 5 BB by making your opponent fold you get 1 BI. 5 bb seems to be low but u will see these 5 BB make the difference between losing and winning.
The SSS is a do or die strategy so exposing to much money or too little money is not good.
With 15 BB doubling up will get you 30 BB.
With 10 BB doubling up will get you 20 bb.Which is just a break-even so you should refill under 15 BB.
By doubling up you get 40 BB which is 2 buyin even with Aces you will lose once in a while.
Pocket pairs are made hands but are difficult to get better on flop turn river while 2 different hole cards can make a two pair straight etc...
Thats why you should leave when table when reaching 25+ BB or play super tight until it is your turn to pay blind then you leave the table.