Speed a lone does not stretch the field or make DC's game plan for you. I played with Michael Haynes at NAU, and that is who Sammy reminds me of "a slower version of Michael Haynes' Mike literally quit the band and walked on at NAU, the minute he stepped on the field he was always the fastest player on the field. Mike later participated in the Olympics trials in 1988 and the only race have ever seen him lose was to Carl Lewis. Mike's transition took him 3 years before he new how to use his speed. Mike, like Sammy, needed to learn how to 'feel his way open". In the beginning Mike thought just being fast and knowing 'his route" was key and he was wrong, this is where Kupp excels, if you know the scheme of the play or what the offense is trying to accomplish and you know the strengths of the opposing defense you can create gaps in the defense.Without ever talking to Sammy, I feel he sometimes not always does not know what the secondary coverage is doing. In basic terms, the defense can do multiple things to disguise the coverage. They can run a man under and zone over the top or it can be a cover 2 with a spy for the slot, but if you know where the play is going and where the other receivers are going to be you adjust your pattern to create more space to work in. Sammy does not transition well in and out of coverages, that is why his best patterns are the go route, the post or the slant, one move and go. Not many receivers will go over the middle the way he does, he accelerates on slant patterns which a lot of receivers won't do, they develop alligator arms, yea Reynolds is fast and can catch, but he does not possess the fire Sammy has going over the middle and Sammy has strong hands and is built like a running back, not to mention there are alot of times he is the fastest guy on the field this is why the Bills traded up for him and drafted him a head of Kahlil Mack. It took Michael Haynes three years to develop into a great receiver with the same system, same QB and Mike was no dummy.
I feel Sammy and Goff would scorch the league with a year under their belt, and in a worst case scenario he would double his numbers. not to mention Sammy keeps everybody healthier, because the spacing is different for the defense when he is on the field, a lot of the runs that Gurley had was created because you have to account for Sammy, safeties can not cheat up, LB's have to make sure it is not a slant across the middle so they are not cheating as much which allows Gurley bigger holes to run through. What Sammy creates in the defense when he is on the field can not be measured. Think of Steven Jackson, when he was on the Rams, we wore him out because many years we had receivers that were fast but scared no one, Donnie Avery, Kevin Curtis defenses stacked the box and crushed us, Sammy prevents that.
