At a point in some baseball player's lives, the sport ceases to be a hobby and becomes a job. The first hint of that shift may come at a pro tryout camp.

Such camps aren't all fun. They're business. A few hours into a camp, the players may hear disappointing words or rejection from scouts running the camp as he makes the first cuts: "Maybe you had a bad day. Maybe I did. But I hope to see you in the future."

On the other hand, often times scouts conducting such camps recommend players who won't be drafted to junior colleges, NAIA, NCAA Division 1,Division II, or Division III universities.

Some of the camps restrict the ages of the players, say from 15 to 22 years of age. From 10 to as many as 700 players can show up at one camp. Some teams conduct only a handful of camps while others hold 80 or more across the U.S., each summer. They may be held in sparsely populated, hard-to- get- to-areas or sections of the U.S., that aren't heavily scouted.

According to the Major League Scouting Bureau, the California Angels, Cincinnati Reds, Florida Marlins, Kansas City Royals, and Pittsburgh Pirates are among the clubs that conduct the most camps.

But the Royals hold more try-out camps than any other major league team, according to Art Stewart, Director of Scouting. This summer, the Royals will hold 82 camps, at which aspiring big leaguers will demonstrate their baseball tools - speed, arm strength, fielding ability, and, for some, pitching ability. Certain players are asked to yet other "invitation only" camps.

Player information cards are filled out on each player. They include name, address, telephone, school, graduation date, height, weight; whether he bats left or right, or switch-hits; his marital status, number of games played last season, the number of innings pitched, his summer team's name, and whether or not he wears contact lens or glasses.

Players are usually asked to bring their own glove, shoes and uniform, and not attend in shorts or cutoffs. They are given numbers after registration and the scout in charge of the camp usually orients them to the events of the day, which amount to various judgements about the mechanics, not the player's past performance, when judging players. In some camps, however simulated game situations allow pitchers, for example, to throw an inning or about 20 pitches. All attendees stretch, jog, and are timed in the 60-yard dash. Even pitchers, says Stewart, for example, may end up being position players and vice versa.

Outfielders' arm strength is tested by throwing from, say, right field to third base. Infielders (other than first basemen) field ground balls hit directly at them, to their right and left, plus slow rollers, then throw from short to first base. First basemen throw to third. Catchers' throwing times to second base are checked in steal-simulation drills.

Pitchers throw to catchers and some are asked to throw batting practice, depending on how many are at the camp and the weather conditions, among other things.

Just who is asked to hit live pitching will depend on how many players attend the camp, the position played, and various grades of skills.

A variety of grading systems are used by major league teams. One grading key scores players this way:
80 = outstanding
70 = well above average
60 = above average
50 = average
40 = below average
30 = well below average
20 = poor

Fielders are graded on their arm, fielding, running, hitting and power. Pitchers are graded on control and on their fastball (for both movement and velocity), curveball, change-up, slider and knuckle ball.

Such camps allow big league teams to see players early in their development and to follow certain players through high school. Ultimately, says Stewart, clubs may then make a wise decision about a player.