While no universal axiom can be made about player effectiveness and age, a rule of thumb can be: an NFL player from 30 years old up is on the downside of his career and is likely to be on a steadily descending performance. So buyer beware.
Does that apply to all? No. It probably applies least to QBs. Perhaps next to Oline. And, there is always the issue of how experience can at times make up for lost quickness and speed; but only to a point.
So to me, to sign a 30 year old WR is risky. Especially if it is to more than maybe a 2 year, quite modest deal and only if the guy is a role player, not your "#1 WR". Sure; there's the Larry Fitzgerald's and Anquan Boldin's of this world. But the reason we talk about them is because they defy the rule of thumb.
All that said, I'd look at 30, 31 year old vets depending on their injury history, their performance graph (especially including the last year), and whether their quickness and speed were still sufficient. But then I'd factor in cost and contract length they seek. The Pats do an excellent job of getting vets to come in and play a role, but it is also playing a role for a fairly short term and relatively small cost. But they do it because they are Super Bowl contenders who vets want to go to, to get a ring (Chris Long), and because they are so solid everywhere that usually they are plugging a hole or two or providing quality depth. But the Rams aren't the Pats.
The Rams need to be wise in where they spend their FA bucks. They are still going to have to build through the draft. And signing a 30 year old WR to anything more than a 2 year deal (or maybe 3 with the guaranteed money done by the end of the 1st year), and at a modest cost, is fool's gold. Signing a 30 year old OG or Center who has been durable and is still performing at a high level? Sure. 3 or 4 year deal probably won't come back to bite them the way NFL deals are typically structured.
I think we'll see the Rams only go after the under 30 guys, and at positions that might surprise. We shouldn't be shocked if they spend big bucks on a guy like Eric Berry. Maybe Zeitler (OG). Maybe Terrell Pryor (WR).
I'm ambivalent about signing Garcon. He's almost 31. But, he might be an Anquan Boldin kind of guy. Even so, you don't give him a big bucks contract imo. He's a 2 year contract, maybe $15 mil. The older guy I'd be interested in is Martell Bennett. He'd be a big help to Goff.
