Writers of Pro Football Prospectus 2008

23 Aug 2009

Does marginal value change during a draft?

At the start of a draft, a player's marginal value is defined as the difference between his projected value and that of the lowest-rated starter at that position. Does this value change during a draft? For example, consider a 10-player league in which each team drafts only 1 quarterback. The top 10 QB projections look like this:

1. Player A: 322 points
2. Player B: 320 points
3. Player C: 312 points
4. Player D: 296 points
5. Player E: 274 points
6. Player F: 273 points
7. Player G: 264 points
8. Player H: 258 points
9. Player I: 253 points
10. Player J: 252 points

The marginal value of Player A, at the start of the draft, is 70 points (the difference between his projection and the projection of the 10th-best quarterback). You have the second pick in the draft, and the fantasy owner with the first pick takes the 11th-rated quarterback, Player K:

11. Player K: 247 points

When you go on the clock, what is the marginal value of Player A?

A. 70 points (the difference between Player A and the #10 QB)
B. 69 points (the difference between Player A and the #9 QB, who is the lowest-rated starter you can select now that someone else took the #11 QB)
C. 75 points (the difference between Player A and the #11 QB, who is now the lowest-rated starter who will be starting in the league this season)

I can't see a clear answer, so I'm hoping someone can tell me. As I see it, answer A has a certain logic, because the owner who drafted QB #11 can take QB #10 as a free agent after the draft. Answer B also makes some sense, although perhaps less than the other two (to me, anyway). And answer C also makes sense, because it fits the original definition of "marginal value."

Opinions? Preference will be given to those backed up by copious amounts of math.

Posted by: Chet Zeshonski on 23 Aug 2009

3 replies , Last at 25 Aug 2009, 4:48pm by tally

1
Re: Does marginal value change during a draft?
by Marcumzilla :: Sun, 08/23/2009 - 10:19am

In giving your logic for A, you say, " because the owner who drafted QB #11 can take QB #10 as a free agent after the draft". If no one is taking a backup during the draft, and QB10, 12, etc. will be picked up after the draft, then the baseline would definitely move up to QB9. Since you are picking QB10 as the baseline, then you are already comparing to the lowest ranked draftable QB, so you wold move it up to QB9 because that is your worst-case scenario.

I'm not throwing in copious amounts of math this morning, but if you don't choose that it changes to B, then you are changing the methodology you are starting with.

In my league that is remaining, the baseline would definitely move up (as we only draft starters, but it's a large lineup). There are other things involved if the bench is taken into account, which is the reason behind one of the settings, which uses bench RBs, and maybe WRs (I don't have it open), into account; but as you're already starting out, you would use B.

2
Re: Does marginal value change during a draft?
by Dan :: Sun, 08/23/2009 - 11:03am

It's B. Marginal value is the value that you add to your team by taking a player now instead of waiting to be the last person to draft a starter at that position. In this case, if you wait then you'd end up with the #9 QB, so marginal value is the difference between the QB you're looking and the #9 QB.

3
Re: Does marginal value change during a draft?
by tally :: Tue, 08/25/2009 - 4:48pm

Actually, the bench situation does affect the marginal value. That's the reason for the top bench RB adjustment in KUBIAK. Since it's unlikely that a team will draft a backup QB early or before other non-kicker/defense starters are drafted, you do in fact use the #9 QB as your baseline.

This becomes a non-issue when using dynamic baselines, by the way...or rather, round-to-round draft tendencies become the central issue with dynamic baselines. Static baselines can only account for so much.

Login or register to post comments