So what are you recommending....a shoe box? Oh wait that's been done.
At the start of each year, I reset my BR to 100k, moving any excess to my personal funds that I place in longer term investment. This conflicts with what Kim Lee tried to teach me, which was one's BR consists of all assets, even home and car. I just was never able to wrap my head around that concept. And I haven't had to as of yet.

Perhaps if the day ever comes that I mortgage my paid for home, to add playing funds to my bankroll, I will be forced to accept that thought process, but I hope such a day (and downturn) never come.
So, I start each year with 100k, half of which must be completely liquid. That amount of funds is rather high for someone that plays my level. But because I play the same rotation of stores, (rather than a great deal of travel as some pros do), I utilize a chip inventory, which results in this higher completely liquid amount than usual.
The "chip inventory" has the benefit of allowing me to enter games, without the dealer notifying the pit, as well as avoid trips to the cage (best camera opportunity for the casino), especially right after I session in which I have been exposed. These two aspects are a real positive to longevity. So while it burns me a little that I have to have a higher than I would like amount "tied up" in chips, making me no money, it is the trade off I must make. It is what it is.

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