[The Velour Fog]

the correct answer is: it depends

some people will be very shaken by 10-15 bi swings (they will happen), others will think nothing of it and just continue grinding. you'll have to ask yourself how much of your roll you can lose and still be able to play your A game, theres really no clear cut answers here.
besides, 20+ bi swings are pretty rare (ive never had one over several 100k hands) if youre beating the games your playing for a solid ammount, 50 bi downswings from a clearly winning player is pretty much unheard of..