It depends on how you count. Is Bademosi a STO player. Is Gostkowski (or is that another category?)
Precisely (no pun intended).
Aside from Gost/Cardona/Ryan Allen, who are clearly a separate category, it's difficult to draw an exact demarcation line for a lot of the other players. Even with a fairly flexible boundary, there's fluidity over time for some players.
I use "snaps
per game active" as a rule-of-thumb, because the counts and percentages listed on pro-football-reference are based on season totals (unless you drill down by player - which reveals yet another layer to the story). The season totals/percentages by themselves don't really present the whole picture, since some players are not active for every game.
Richards was active every game, so dividing his 309 total ST snaps by 16 = 19.3/game active. His listed percentage is 68.5% of all ST snaps for the season.
Ebner contributed "only" 172 ST snaps (38.1%), so he looks like a relative slacker until you divide by the 9 games for which he was active/available for snaps = 19.1/game active.
Another rule-of-thumb ...
Even though the total ST snaps varies for each game, basically by the total drives by the two teams, the number of non-PAT/FG snaps available to play per game is +/- 20, generally speaking. So, a player who averages between 18-22 ST snaps per game is likely playing on both return units and both return-defense units (the "big four") - which makes him a fairly critical player on ST, whose snaps will need replacing when he's not available.
Personally, I don't count a player as STO if they fulfill a position. So, Bademosi is starter on special teams and a #5 corner.
Perhaps it's the effort to draw some clear distinction between "STO" and a legit reserve player that's the problem. Something like "ST-primarily" may be a more useful distinction.
Bademosi started three games at RCB, during which he played a total of 26 ST snaps. In the other 13 contests, he averaged 19.4 ST snaps/game. Those three games accounted for 184 of his season total 214 snaps on defense.
While his performance in those two games
looked pretty good and was statistically very good, the fact that Butler was targeted way more than Bademosi in those games should be a bit of a caveat, or at least raise the questions - "Was Bademosi not targeted because he was smothering his guy? Or was he not targeted because opposing QBs were way more familiar with Butler's vulnerabilities? How might that have played out differently if Butler had been the one injured and Gilmore the one playing? Would Bademosi have been tested more thoroughly in that circumstance?"
So
maybe he's a legit #5 CB - under the right circumstances, at least - but he's still
primarily a special teamer. He only appeared on defense in two other games, one of which was the season-ender versus the Jets.
The contrast would be JJ, who played 30% or more of the D-snaps in 13 games, including a 12-game stretch in which he averaged over 50% of the D-snaps - while also averaging 18 ST snaps/game. That's also a sharp contrast to his rookie season (2016) when he played a total of only 64 D-snaps while averaging 19.2 ST snaps per game. In 2016, he was "STO" perhaps. In 2017, though, he became a legit #4 CB while still a critical special-teamer. In 2018?
Another contrast might be Marquis Flowers. He played 125 of his 209 season total ST snaps during the first 8 games of the season, and only 32 of his 283 season total D-snaps. So, during the first half of the season, he was
primarily a special-teamer, averaging 15.6 ST snaps/game (three of the "big four" units). After the BYE, he was
primarily a defensive player (similar to Nink's first season with the Pats in 2009).
Hollister's season was, of course, the reverse of Flowers' season.
Anyway, in terms of final roster cutdown decisions, a player who's an excellent special teamer and who can also
maybe contribute some effective scrimmage snaps (under the right circumstances) has generally been preferred. And then, there are those younger players in whom the coaches see some significant developmental potential, but who have been, thus far, almost exclusively special teamers (thus, the Pats kept JJ and shed Coleman).
But there's also usually been +/- 7 players who are apparently excellent (high-usage) special teamers who make the roster, even though they're relatively mediocre (or useless) in scrimmage play.
And, obviously, ST ability is often,
but not always, a factor in which reserve player to keep.
For instance, no doubt that a lot of forum members view Roberts as being no better at LB than Freeny. Freeny is a 19.2 ST-snaps/game guy, while Roberts contributes almost nothing on ST. Nevertheless, the Pats kept Roberts over Freeny last September. Maybe that means that Roberts actually
does have a BB sex tape. Or, maybe it means that the coaches saw enough developmental potential with Roberts (in only his second season) and also had enough guys who could cover ST, that Roberts ultimately had more value to the team.
A lot of folks think that McClellin contributed zippo in his 380 rotational D-snaps in 2016 and, thus, had no value. But he also played 15.6 ST snaps/game (IOW, he was doing much more than just trying to block FGs and PATs).
Anyway, in 2018 cutdowns (six months from now), there may be a decision between keeping Hollister or Will Tye at TE (though they could both be kept, depending on how other things shake out) in which ST contributions could be a factor.
Tye (same size as Dwayne Allen, BTW) was a pretty successful receiving TE for Eli with the Giants in 2015-2016, catching 90 of 132 (68%) for 859 yds (9.5 YPC) and 4 TDs. In his three games with the Jets at the start of 2017, he caught 4 of 6 for a 9.5 YPC. However, he played only 41 total ST snaps in his two seasons with the Giants and only 17 with the Jets (all in week-1).
In contrast, Hollister ended up playing 188 ST snaps with the Pats in 2017, averaging 15.7 per game over his last 11 appearances (note that the Pats kept Hollister over O'Snotmessy, another TE/special teamer).
Since Richards can't play defense, we need another #4 safety.
Agree 100%.
