Match-three and the workday: when to open, when to close
Three honest windows — and 'one round to break the streak' means close the tab.
Match-three fits a workday at exactly three moments: booting up and waiting for the system, waiting for the coffee, and the last ten minutes of lunch. Outside those windows the genre starts taking more than it gives, because the short-round structure — its greatest strength — becomes bait when you have unfinished work.
The sign that you have overrun is specific: you catch yourself saying 'one more round to break the losing streak'. A losing streak does not exist in a casual game; it only exists once you have attached feelings to the score. Closing the tab at that moment is the correct move, and the game will still be there tomorrow, holding no grudge.
One layout trick from working players: bookmark the portal's home page, never a running board. The home page shows every shelf and ends your attention naturally; a running board invites you back into the round. That difference is the difference between five minutes of rest and fifty minutes gone.