Avoiding performance-chasing after one fund category has a great year

Every year one fund category seems to win the performance charts, and the argument for moving more money into it sounds persuasive in hindsight. I know chasing last year's winner is a poor investment process, yet I'm still drawn to those graphs. I'm trying to write down my target allocation and a rule for reviewing it only at set intervals. What makes it easier for you to ignore impressive recent returns without ignoring meaningful changes in your own goals?