ADP (Average Draft Position) is a metric that most fantasy baseball players use while researching as well as while drafting. ADP refers to the average overall pick that a player is being selected in drafts. For example, if I took three draft results and saw that Bryce Harper was drafted 1st, 2nd, and 3rd overall respectively, his ADP for these 3 drafts would be 2nd overall. It's a relatively easy concept to understand. That said, too many people use ADP incorrectly and to their detriment.
While ADP is a nice indicator where a player is being drafted on average, there are problems with how people use it. Here are a couple common ADP use cases I feel are flawed, but also how to use them more correctly:
While in a draft, using ADP as a firm gauge for player selection.
Not all fantasy baseball players are created equal; meaning, we all differ in how we do research, and how much research we put in. Many casual fantasy baseball players do little prep and rely heavily on ADP data during their live draft. That's fine for a casual player who might not take things too seriously, however if you are doing this, it may be difficult to get players you want at certain points in the draft.
Example: player A has an ADP of 220 overall. To get to that 220 ADP, hundreds of drafts already took place to calculate this ADP, and in those drafts, player A wasn't selected at spot 220 each time. He likely went 160 or lower in some drafts and 280 or higher in others. If you plan on sticking very close to the actual ADP numbers, there are likely going to be players you miss out on. If you really want player A, it may make sense to reach a bit earlier than what their ADP indicates to ensure you acquire them.
At the same token, you don't want to reach too early in drafts and drastically overpay for someone either. If someone has an ADP of 80, selecting them in the second round isn't a wise choice. Earlier in drafts there will naturally be less variance in players ADP numbers. However as the rounds go on and the talent pool gets thinner, one can make an argument for drafting a number of similar players in the middle to later rounds.
Because every draft is unique, there isn't a magic formula that works for all cases. Rather than simply relying on ADP data for your draft guide, I would strongly recommend that you do your own research, form your own rankings and opinions. I also understand that's a lot of work and not for everybody. If you are going to rely on ADP data during your draft as a guide; when in doubt, I would suggest reaching for a player earlier than ADP indicates. The alternative is waiting too long, missing out, and regretting the decision.
Using ADP data to create your projections and rankings.
For those more involved (like myself), creating your own projection and rankings can be a very fun and rewarding experience. In addition, the research that goes along with that is the best way in my opinion to fully prepare for a draft. Now, when creating your own rankings, it's natural to look at your data and compare it to ADP data to get a gauge of where the greatest variances are. If you happened to miss some player news and are way off on someone, looking at the ADP data can be an effective way to catch that type of mistake.
It can also impact your own rankings negatively. It's just as easy to assume that you're wrong when comparing your rankings to ADP. If everyone else has player B ranked at 100 overall and I have him ranked at 55, how could I possibly be right compared to the rest of the world?? This is an easy trap to fall into. Here's how I try to approach using ADP data when I'm creating my rankings:
This is really high level and there's more than goes into it, but it's an easy way to make my point. By using this method, I try to give myself a safety blanket in case I am grossly off with a projection of a player. ADP trends help to catch that. At the same time, I try not to get sucked into the vortex of believing that ADP data has to be more accurate than I am.
If you do in-depth research and are confident in your projection, it's perfectly fine to differ from ADP, even by a lot. It's also ok for everyone else to be wrong.
One final thing to keep in mind: If you always stick to ADP data, you're sticking to averages and will draft an average team. Average teams usually don't win.