Why leaderboards are best throttled?
By publishing your leaderboard at specific point in time - for example weekly - you create a 'news event' that players can get into the habit of coming to the leaderboard to check their score for the previous week.
This technique has been used effectively by news organisations for many years. For example Forbes publishes its Rich list once a year, the Word Tennis Federation publishes tennis rankings once a week. It creates a shared scorekeeping rhythm valued by managers and players alike.
This also helps players create good habits - checking scores each week and then optimising their performance is a great scorekeeping habit that sustainably drives continuous performance improvement.
Players can always check to see that their latest scores have been tallied towards the next publication of the leaderboard by clicking on Latest Scores on the leaderboard itself.