In fantasy football, not every position offers the same supply of reliable players. For example, there are usually only a handful of running backs who get heavy workloads and touch the ball often, while there are many more wide receivers who can put up useful points. When a position has few good options, the ones who exist become more valuable, because waiting too long to draft one means you could be stuck with a weak player all season.
Positional scarcity shapes draft strategy. Many managers use the tactic of drafting scarce positions early, like running back or tight end, and waiting on deep positions like quarterback or wide receiver. The key is to compare the gap between players at each position rather than just looking at total points. If the drop-off after the top tight ends is huge but the drop-off after the top ten wide receivers is small, it can make sense to grab the tight end first.
Keep in mind that scarcity can change from year to year and depends on your league's scoring and roster rules. Leagues that start two quarterbacks or use point-per-reception scoring can make certain positions much scarcer, so it's smart to check your league settings before deciding which positions to prioritize.