The Seattle Mariners announced 34 non-roster Spring Training invitees on Friday. These are players who are not on the 40-man roster - many of them some of the top prospects in the organization - who will nevertheless be able to compete in Spring Training exhibition games in Peoria as a test of their mettle in a more MLB-like environment. Not all of them are close to making it to the Show, but they will still afford the attention of Mariners-world as to where they are in their development. For guys higher up in the farm system, their performance in Peoria might make the difference between starting the year in Cheney Stadium or T-Mobile Park.

This is the first of a series of four articles going over some of the higher-ranked prospects in the Mariners system who have received the Spring training invite and the first of two covering some of the hitters.

Before we get into the prospects, it’s important to familiarize yourself with the 20/80 scale, which baseball scouts use to evaluate players’ abilities or “tools”. Each tool is rated on the scale, where 50 is MLB average, 20 is about the lowest things get for an MLB player, and 80 is about the highest. In statistics terms, each increment of 10 is one standard deviation from the mean, so roughly 95% of big league batters have a hit tool between 30 and 70. Some systems of scouting differentiate between present grades and projected future grades, while others only give those projected future grades. These analyses give the scouting profiles from FanGraphs (which separates present and future) and Baseball America (which does not).