What is the 1/3,2,6 strategy?

The 1-3-2-6 system is a win-streak progression, not a loss-chasing one, so it doesn't help you recover a losing streak. The sequence applies only to four consecutive wins: after the first win you bet 3 units, after the second win you bet 2, after the third you bet 6. Any loss resets you back to 1. You don't raise after a loss.

What it actually does is bank the profit from earlier wins while risking little. After two wins you've got a net profit of 4 units already, and the 6 is a free roll on someone else's money. If you lose at the 6 stage you still walk away with 4 units profit. That's the whole appeal.

Your real problem is the hour where you went 50 up then gave it back. No system fixes that because your tilt after four losing hands will blow the staking plan. A 100 euro bankroll at a 2 euro minimum table gives you 50 flat bets. With the 1-3-2-6 you only need about 15 units to survive the exact same losing streak, but one bad sequence at the 6 unit step takes out 12 euros in a single hand. That's a sixth of your roll.

I've seen people flat bet for two months and get ground down by the house edge, and I've seen people use 1-3-2-6 for an hour and get skewered by variance. Neither beats the game. If you actually want to protect your 100 euros, the rule is: 20 hands of flat betting, hard stop when you're up 40, or if you lose 8 flat bets in a row you quit for the session. The progression is a toy, not a bankroll plan.

It also means you're restarting from 1 on a loss. If you never get past the first step, like in a cold shoe, the system just drains your roll at minimum stakes but without any recovery. Just an fyi.

I tested a 6-deck shoe, 20 minutes? The thing don't recover losing streaks faster than flat betting, cause it don't do anything on losses at all. You're only chasing wins up the ladder. The only way it feels faster is if you hit a lucky run of four wins. Then you're up 12 units in four hands.

Play at tables with surrender for soft 17? Doesn't change the staking math, honestly. And side bets are a tax. Ignore them. Even blackjack is bad odds; surrender only clips the worst of it, but the sequence doesn't interact with it.