Handling touchdowns in fantasy football analysis requires some nuance.

On one side of things, touchdowns are vitally important. They can salvage otherwise weak performances from low-volume players, they can give a player league-winning upside, and you're not going to find many correlations stronger than that between touchdowns and fantasy points scored.

On the other hand, zeroing in too closely on touchdowns scored in the past is a fool's errand. There's very little correlation in a player's overall touchdown number year-over-year, making past touchdowns a pretty weak way to try to predict future touchdowns.

So we want to chase touchdowns in the future, but as soon as they happen (or don't), it can serve us well to take the results with a grain of salt unless they can be backed up with a deeper look.

The variable nature of touchdown scoring doesn't mean that we can't predict them, though. Previous touchdowns might not help up identify players likely to score more in the future, but there are plenty of factors that do.

A player in a high-scoring offense, for example, stands to have more scoring potential than one in a low-scoring unit. And a player seeing more touches will have more opportunities to find paydirt than one rarely touching the ball -- especially as you get closer to the goal line.

Even though passing touchdowns are typically worth only four fantasy points, compared to six for rushing and receiving, they are no less important to fantasy production.

Over the last three years, the correlation between passing touchdowns and fantasy scoring among quarterbacks has an r-squared value of 0.95 -- meaning that they are about as closely linked as can be. If we include rushing touchdowns into the mix, the correlation gets even stronger.

If you're reading numberFire, you're likely familiar with the idea of drafting a quarterback late and using the waiver wire to address the position on a weekly basis. But that doesn't mean you're not looking for upside.

Once we get outside the obvious top-tier of passers -- guys like Aaron Rodgers, Tom Brady and Deshaun Watson -- the key to finding a quarterback who does end up being an every-week lock is finding one who is going to get into the end zone. A lot.

Here are five guys with the potential to do exactly that in 2018.