So, how do these contracts work? Each pick appears to have a pre-set value. Is that the overall contract value for the player drafted there? So Lee for example at pick #170, it says the value is $342k. Is that guaranteed money? Over how many years? I just am not familiar with how this works...
ooh boy, i'll do my best:
Each pick in the top 10 rounds has that pre-set "slot value" assigned, but there is no guarantee the drafted player gets it. The purpose of the pre-assigned value is mostly to calculate how much money a team has to spend on ALL it's draft picks. For example, the Pirates have a total bonus pool of $16,185,700, which is the highest of any team (mostly because they have the highest picks that have the highest slot values). The Phillies only have $5,185,500 because they pick towards the end and lost some picks for signing free agents.
That said, the Pirates could spend $16 million on one player and theoretically sign the rest of their picks a $10k bonus -- how you distribute the money is up to the club (obviously both the team and player need to both agree)
Caveat: if a team doesn't sign one of their top 10 round picks, they lose the money from their bonus pool. That's why top 10 round picks almost always sign -- they've usually already agreed to terms prior to the team drafting them.
So if the slot value for Bennett Lee is $342k, they could theoretically have come to terms where they only pay him a $200k bonus and use that savings ($142k) for other picks. You will sometimes see seniors with no leverage get taken in the first 10 rounds and sign for very small bonuses (e.g. $10k) for this reason -- Parker Dunshee and Ben Breazeale were top 10 picks like this, Pierce Bennett might be a fit this year.
After the top 10 rounds, the rules change a bit. You can give a bonus up to $125k with no penalty, but there's no slot value -- so no advantage for signing a player underslot, and no penalty for not signing a player. That said, you will sometimes see guys taken after the top 10 rounds sign for big deals using money saved from the first 10 picks -- Isaiah Lowe is one example from last year, who signed a big overslot deal (~$400k) despite being drafted in the 11th round.