Baseball America does an excellent job of scouting and projecting players in the major league drafts.
In the last mock draft, BA notes that president Theo Epstein was part of a Cubs contingent that scouted Kennesaw State catcher Max Pentecost
in last weekend’s Atlantic Sun Conference Tournament. If one of the three touted pitchers doesn’t
fall to the Cubs at No. 4, the team could sign Pentecost to a
"money-saving deal" that would allow them to spend more in the later
portions of the draft. BA’s current projection is for that very scenario
to play out.
A money saving deal is paying for a player under his slot value price, and then use that savings to sign a player lower in the draft above that player's slot value price. It is moving first round money into the second or third round in order to sign a player who has fallen (by performance or injury but still has upside potential) to a near first round deal.
Why would a player sign a below slot deal? Because, in essence, the prospect is being drafted higher than his real projection. He may be a good player, even a first rounder, but in an objective field may fall to the bottom half of the round (and millions of slot dollars less). If one compromises on that value toward the projected slot value, the savings is what teams can use in the signing pool for other players.
The only other avenue to bring down slot values is to draft college seniors and offer below slot. The reason is simple; if the prospect does not sign he has to wait a year to become a free agent. A year without competitive ball (rookie league or college) is a huge negative on a player's development track. On the flip side, high school draft choices have more leverage to say "no thanks" and return to school.
It is not to say that the Cubs don't need to draft a first round caliber catcher. The Cubs system is barren of catching prospects, so signing Pentecost can be justified without the contract savings loophole.