The worth of an offensive lineman is best determined by both his physical and mental abilities. In other words, strength, power, foot quickness, mobility and fundamentals are the foundation for being a solid offensive lineman. What separates the good from the great are the intangibles.
It takes a special person to be an offensive lineman: someone who places personal pride above glory in terms of his attitude toward the game. Physical skills are important but it's the "fight" and the effort put forth that make the difference. The very best at the position are tough and aggressive to the point where they do whatever it takes within the rules of the game to finish the play and win their one-on-one battles.