The 2018  NFL combine is well underway, with the country’s top prospects undergoing intense scrutiny by NFL scouts, coaches, and executives. There are a lot of factors that go into evaluating prospects — medical tests and interviews are nearly as important as the on-field drills. There’s a lot more going on than what fans see on TV at Lucas Oil Stadium.

That’s not to say the on-field workouts are unimportant. Quite the opposite, in fact — top prospects have to put in a good showing and prove they’ve been taking their offseason conditioning seriously. The players who show up out of shape and sandbag their workouts will get weeded out pretty quickly. The combine is about the best of the best earning their reputation, while some under-the-radar prospects are eager to make a name for themselves.

So with all that in mind, let’s go over the workouts that all players will go through as they get ready to turn some heads and potentially make some money in the  NFL draft .

40-yard dash

There are legitimate questions about how useful the 40 time really is — after all, NFL players won’t be running in a straight line in warm-up clothes on Sundays. But despite those concerns, there’s no questioning that the 40 time is the biggest event of the Combine, and the one most fans will be tuning in to see.

This event is just what the name implies: a 40-yard timed sprint. Beyond raw speed, scouts can also use this drill to test how fast a player gets out of his set position and gets up to full speed. This is a particularly important skill for wide receivers and cornerbacks, where timing is everything in running/defending routes.

Wide receiver John Ross holds the modern record for fastest 40 time in combine history,  having run a 4.22 in 2017 .

Bench press

This is a relatively simple drill. Players have to lift 225 pounds for as many reps as possible. It’s mostly a showcase for upper-body strength, and the big linemen typically shine here. However, there’s a different element to judging this drill — a high number of reps is usually a sign of good endurance and cardio. The players who do well here will show scouts they have a commitment toward staying in the weight room.

Vertical jump

Players start from a standing position and leap as high as possible, touching the highest flag they can to measure their vertical leap. This drill is mainly used to judge wide receivers and defensive backs on their ability to win contested catches or break up passes, respectively. But it can also be used to see how well players utilize their lower-body strength to explode out of a standing position.

Wide receiver  Chris Conley  set the modern record for highest vertical leap in 2015, when he jumped up to 45 inches.

Broad jump

Another jumping drill, this is similar to the Olympics’ long-jumping event, except players must start from a standing position rather than getting a running head start. The goal is simple — leap forward as far as possible and stick the landing without stumbling. Much like the vertical leap, the point of this drill is to measure lower-body strength and quickness out of the jump. Body control is also important, as players will get dinged by scouts if they can’t land cleanly.

The modern broad jump record was set in 2015 by defensive back  Byron Jones , who impressed with a 12’3 leap.

3-cone drill

This is one of several drills that challenges players’ quickness and cutting ability on the fly. Three cones are set up in an L-shape, with players lined up in a two-point stance on the first cone. They run 5 yards to the second cone, pivot back to the starting line, move around the second cone again, and make their way to the third cone, which they must weave around in a fluid motion before moving back to the line.

The three-cone drill is a big test for linemen and running backs, who need fast cutting motions and quick instincts inside the trenches. It’s also a useful test for receivers and defensive backs capable of changing direction on a dime.

Receiver Jeffrey Maehl holds the modern record with a 6.42 time in 2011.

Shuttle run

The shuttle run is actually broken up into two distances: 20 yards and 60 yards. At 20 yards, players start in a three-point stance before running out 5 yards to their right side. Then they must sprint 10 yards to their left, before going 5 more yards right to the finish line. The 60-yard run has a similar setup, except players must run 5 yards and back to the starting position, 10 yards and back, and then 15 yards and back to complete the drill.

Much like the three-cone drill, this is designed to test a player’s agility and lateral quickness. Big linemen in particular will be challenged to drop their hips and make the necessary cuts, testing their ability to adjust in the trenches fast enough.

The modern 20-yard shuttle record still stands 11 years after cornerback  Jason Allen  ran a 3.81 time in 2006. At 60 yards, wide receiver  Shelton Gibson  stands alone with a 10.71 mark in 2017.