The baseball rule book may be as complicated as any in professional sports, and a recent ESPN article showed just how little some MLB players/coaches/analysts know about the more in-depth rules of our national pastime.

With that in mind, I gave the rule official rule book a quick scan on MLB.com, and compiled some of the more strange rules that the rule book contains.

Here are seven MLB rules you might now know exist:

Rule 2.00: "...An INFIELD FLY is a fair fly ball (not including a line drive nor an attempted bunt) which can be caught by an infielder with ordinary effort, when first and second, or first, second and third bases are occupied, before two are out."

The infield fly rule can be a cause for confusion sometimes, and there was some controversy regarding an infield fly call in the Braves-Cardinals postseason game last year.

However, the little-known part of this rule is that an infield fly cannot be called on a bunt. Generally, bunts don't get very far off the ground, but there are occasions where a hitter pops one straight up in the infield, so I was surprised to learn that no bunts can be called infield flies.

Rule 3.09: "...Players of opposing teams shall not fraternize at any time while in uniform"

This is one of those archaic sports rules that no one follows and no one would ever enforce. Players regularly converse prior to games, during batting practice, and on the basepaths between plays once the game begins.

Rule 4.03: "When the ball is put in play at the start of, or during a game, all fielders other than the catcher shall be on fair territory."

There's no logical reason why a fielder would ever position himself in foul territory prior to a pitch being thrown. However, it's not only a poor decision, but in fact a violation under the rules. All players, aside from the catcher, must be in fair territory once the ball is live.

Rule 4.03a: "The catcher shall station himself directly back of the plate. He may leave his position at any time to catch a pitch or make a play except that when the batter is being given an intentional base on balls, the catcher must stand with both feet within the lines of the catcher’s box until the ball leaves the pitcher’s hand. PENALTY: Balk."

Most understand that a catcher has to remain in the box behind home plate until the pitch is thrown; that is the reason why catchers hold out their hand/glove on an intentional walk rather than simply setting up behind the opposing batter's box. However, the fact that a balk can be called on the catcher for being outside of the box was news to me.

Rule 6.08c: "...If a play follows the (catcher's) interference, the manager of the offense may advise the plate umpire that he elects to decline the interference penalty and accept the play. Such election shall be made immediately at the end of the play..."

Catcher's interference is a somewhat rare occurrence, but it does happen from time to time. It is called when a batter makes contact with a catcher's glove on the swing, and as a result is rewarded first base. Should the batter manage to get enough bat on the ball that he makes solid contact and gets a hit on the play, however, the manager can opt to take the result of the play as opposed to the interference penalty of first base.

Rule 7.05b: "Each runner including the batter-runner may, without liability to be put out, advance three bases if a fielder deliberately touches a fair ball with his cap, mask or any part or any part of his uniform detached from its proper place on his person."

It's commonplace for little kids playing a neighborhood game of baseball to throw their gloves at the ball to try to stop it or catch the ball in their hat for one reason or another. In the MLB, however, taking off any piece of your uniform and touching the ball with it is an immediate three-base penalty.

Rule 8.04: "When the bases are unoccupied, the pitcher shall deliver the ball to the batter within 12 seconds after he receives the ball. Each time the pitcher delays the game by violating this rule, the umpire shall call “Ball.""

Another rule that is never enforced: a pitcher actually has just 12 seconds to deliver his next pitch once he gets the ball back from the catcher if there are no runners on base. Last season, the Wall Street Journal did an interesting study on how quickly each pitcher in the league works. While this included all situations, not just when the bases are empty, it's safe to assume a sizable quantity of pitchers violate this rule on a daily basis.