Adjusting when on the move.  Can the player find the ball quickly when the play moves away from him?  How quickly does he adjust to the offense as a play unfolds?  Look for a player to be able to react quickly when a lineman pulls on offense, and to adjust to second-level offensive blockers.  A good "flow" to the ball is a sign of great instincts, where the player closes on the play gradually and in control, reducing escape angles without over-committing.

How well has this player absorbed the defensive playbook?  This is a very difficult trait to evaluate with no knowledge of the particular scheme being run by the defense.  When you can, take note of any pre-snap adjustments that the player makes or orders others to make, and note the effectiveness of the adjustment.  Normally the reads involve assigning gaps; knowing what techniques are favored by, or best suit particular D-lineman can help in judging the accuracy of the calls a LB might make.

A measure of the LB's ability to blow up a blocker.  Can be defeated via speed and quickness or through brute strength.  Look for a LB to engage proactively rather than being sought out by blockers, and to have the advantage from the start.  Also look for LBs who can evade blocks entirely, leaving them free to take on the ball carrier.

For a LB who gets caught up in a block, an important trait is the ability to forcefully extract himself.  Usually this is a case of tenacity vs. brute strength, as most blockers are usually linemen or FBs.  Some LBs shed by pulling away violently enough that the blocker can't hang on, while some drive and try to pull through the block hoping to disrupt the play.  Above all look for LBs who fight to shed quickly, because the longer the block holds the less chance they have of breaking it.

How well does the player fill his gap and wrap up the tackler in a short area? Inside tackles are often tremendous collisions.  How often does the player come out on the winning end of a big hit?  How well does a player set up for the tackle in a short area?

How well can the player pursue  the ball carrier through trash?  Can he keep his balance around downed blockers?  How is his closing speed when pursuing a ball carrier?  "Sideline-to-sideline" is a term often used to describe a LB who is effective at getting to the edges and making the play.

The keys here are hips and feet.  You want the hips to be loose and for the player to be able to turn easily to either side, and quickly.  Good core strength is key here.  For the feet you want nimbleness, quickness and the ability to get depth fast.  A player who can get deep quickly and cover sideways with good range tends to have good hips and feet.

In a zone scheme, the player should have good instincts and routinely set up in the right part of the zone.  To evaluate this, try to find the number of opponents in his area, compared to the opponents in other players areas.  He should have at least one responsibility and be targeting him through his zone.  For man coverage, speed and quickness are the primary factors, as well as the physicality to match up near the line of scrimmage and with larger TEs.

When tackling, look for a player who is also attacking the ball without losing tackling leverage.  Does the player consistently finish off coverage, extending to deflect passes?  How well can he attack the ball in the air or adjust to a fumble?

Timing might be the most significant factor here, followed closely by awareness.  Does the player slow up when a chipping RB moves towards him?  Does he maintain his urgency through the blitz and finish off with a wrap-up tackle?  Can he stay under control?  A player who demonstrates superior avoidance when accelerating through the line usually grades out highly, as they are demonstrating above-average control.  Watch for flailing hands, and any time when the arms get above head level, as that indicates a player out of control and off balance (don't confuse this with the occasional high-speed swim move!)

What type of rusher is he?  Finesse or power?  Does he rely on speed?  Does he use his hands (swim, rip, club)?  Does he engage blockers or try to avoid them, or does he hesitate when attacking?