Tenpin

Went bowling on the weekend and scored 182 and 199 over two games. I was in the Australian Corporate Games last year and came 4th with a 620 series (three games, 212, 200 & 208). I used to play league about 10 years ago and couldn’t barely manage a consistent 160 each week. What gives? Why can I go out and bowl near or over 200 games once a year, but can’t do it each week? Is it like beginners luck each time? I was considering joining a league again, maybe I should join the slow-pokes, which play once a year instead of once a week!