Bigger isn't always better, but size matters

The list of big receivers who have flopped in the NFL is a long one, and there are countless more who have had just decent pro careers instead of fulfilling lofty expectations coming out of college.

That said, all things being equal, give me the big guy every time.

There's a reason -- plenty of them, actually -- that most personnel evaluators agree on this subject. As much as I love WR Wes Welker (5-foot-8, 185 pounds), it's QB Tom Brady and WR Randy Moss who make that offense in New England. And in New Orleans, why do you think WRs Devery Henderson (5-11), David Patten (5-10) and Lance Moore (5-9) are open so often? Because defenses got tired of being bludgeoned to death by 6-4, 225-pound Marques Colston and put extra defenders on him.

All kinds of factors go into the evaluation and projection of wide receivers in the NFL, more than at most other positions. But size -- and we're talking arm length and body weight here, as well as height -- is a prized commodity because it's relatively rare. You can teach a player to run sharper routes, read coverages and maybe even improve his speed. But you can't teach him to be taller.

That doesn't mean that Colston, for example, is necessarily a better football player than a Welker or a Santana Moss. Doesn't even mean Colston does the same things in a bigger body. Colston's quickness and speed simply don't compare. But his frame literally makes him a bigger target in his team's offense and forces defenses to adjust their coverages and schemes to account for him.

Bigger receivers have a larger natural catch radius, giving a quarterback more room for error. They generally get off the line more easily against press coverage and are less likely to be knocked off their routes. They're better able to attack all levels of the field. Even a size receiver who doesn't have great wheels still can make explosive vertical plays. The Michael Irvins and Cris Carters of the league have excelled as downfield targets because of their ability to position themselves on a defender, leave their feet and extend to go get the ball. They aren't easily outmuscled or pushed around. They have the strength to pin a defender's inside arm, lean on him, push off his hips, butt or back and get over the top to make the catch. They're difficult to bring down after the catch.

Not surprisingly, defenses often respond to these receivers by rolling a safety over the top, bracketing them with a linebacker and double-teaming every which way they can. Think that doesn't open up an offense to give others better opportunities? Even a big receiver with average overall talent is a threat worthy of extra attention in certain situations. The red zone -- where a size receiver can use his frame as a shield on a slant pattern or to box out a smaller cornerback on a fade route -- is a perfect example.

Two other qualities that sometimes get overlooked in big receivers: durability and blocking. Personnel evaluators worry about smaller guys' ability to hold up over a 16-game season. Larger receivers seem to take the day-to-day and game-to-game poundings in the NFL better. And they're certainly better equipped to screen off or knock down defenders on a perimeter run or quarterback scramble. Desire is a huge component, but there's a reason you're likely to see Brandon Marshall (6-4, 230) throw a dozen effective crackback blocks before you see Bobby Wade (5-10, 186) deliver one.

Even in the NFL, it takes all types. There always has been a place for smaller receivers in the league. Always will be. And regardless of the position, if someone can play, coaches will find a way to get him onto the field. But when push comes to shove and personnel men are forced to make a tough choice between different-sized receivers, they'll almost always go big.

Scouts Inc. watches games, breaks down film and studies football from all angles for ESPN.com.