Bankroll mgt is very much like managing your chips at the table. You decide your level of risk by 2 factors. A) Your perceived chance of winning and B) your need to stay in the game. Example: Your bookie still offers Patriots -3 but the real Vegas line moved all the way up to -12. You may be tempted to go all-in on -3 but then you are out of the game if you lose. No one would fault you for taking the opportunity to quickly increase your bank roll. Its your choice. You go big and risk losing and having to come back months later after putting in overtime at the job... or maybe you increase the bet only 5x the normal play.
Poker players tend to make better sports bettors. They understand its a law of averages and that they need to have a certain win rate to overcome the rake.
With sports betting there tends to be this idea, especially with new bettors, that you can "pick a lock" or if you lose 4 games in a row you are getting buried or games are fixed. Unlike the rake which poker players see as the cost of playing, sports bettors see the vigorish (10 in the -110) as something only losers pay. New sports bettors don't have the benefit of getting practice and to see a lot of performance data at once. A good sports bettor needs a good memory (a spreadsheet).
You can find a guy in the sports betting forums taking verbal swings at another guy who shared a losing +800 underdog play he loved. The guy with the 8-1 pick was calculating that if the game played 24 times the dog would hit more than three times. The guy who was upset that he followed the pick, expected it to hit right then. If one of those two gents played poker before, you can guess which one.