I agree that Belichick has had problems acquiring safeties and keeping them healthy. Ihedigbo was, and probably still is, a valuable commodity as a special teamer and #4 safety. Sergio was an OK special teamer that Belichick hoped would be better. However, the problem was not that these guys were terrible starters. They were never intended to be close to getting lots of reps on defense. Belichick didn't have enough quality at the top 3 safety positions AND there were two injuries that forced guys like this to start.
SPECIAL TEAMS
In addition, one of the reasons that Belichick is one of the greatest coaches ever is his attitude toward special teams. Special teams are important to Belichick.
First the specialists are important. Kickers are paid serious money. There is often competition for punter and long snapper. Belichick uses starters at returner (Welker, Brown, Edelman, Hobbs, and others).
Starters are often key players on the special teams units. Some teams are not willing to risk top players in these roles. In addition, Belichick keeps 2-7 players who are on the squad because they are special team "starters", key player son the special teams. Yes, these players are usually emergency players at their positions, but the hope is they never get on the field as position players. The patriots have had this philosophy for many years. We have always had at least a couple of players who are on the team as "special teams only" players. These players are NOT on the bubble. Guys like Slater have special team roster positions, and are often much more important and likely to make the team that the bottom 7 players. The bottom seven often do include special teamers, who are sometimes cut and re-signed several times during the year. But make no mistake. Belichick will often carry many players who primary function is special teams.
Posters disagree with belichick's approach to special teams every season. Every season, posters say that we cannot "afford" to carry a LB or S who are primarily special teamers. And, every year, Belichick disagrees.
THE CORE AND BOTTOM TEN POSITIONS
The bottom ten positions can be used for lots of things: position backups in case of injury, developmental players and special teams. To me, 43 roster players are needed in a addition to addition special teamers. These 43, plus additional special teamers, will get almost all the reps.
OFFFENSE (19)
QB (2)
WR (4)
RB (3)
FB (1)
TE (2)
OL (7)
DEFENSE (19)
DL (7)
LB (5)
CB (4)
S (3)
SPECIAL TEAMS (5)
K (1)
P (1)
LS (1)
ST (2)
The highest priority in the bottom 10 positions for winning a game, or winning this season is likely to be special teams. Then, we often have developmental players (including rookies). Position backups, in addition to what is included in the 43, is often 3rd in priority.
To put in another way, if the 43 positions above were filled, I would first add our top draft choices and then look to special teams. For example, the top 43 likely doesn't include a kick returner.
My light-hearted post has produced a more serious response than I expected and many of the points I'd make have already been made.
I don't need any lessons in what BB DOES and, of course, I'm thrilled that he is the coach of this team. In fact, never more so than last season when he responded to the most awful situation imaginable with the authority of a true leader.
But, that said, as we get older (BB, me, the Pissah) we tend to get more conservative. We have a lot of experience to draw on and we naturally see new situations in terms of things we've seen before. And we know not just that BB thinks Special Teams are valuable enough to have roster spots committed to them but how he sees the parts of it.
But it's arguable (and people on this thread have argued it) that the game has changed. Essentially, the kick-off can be eliminated if you have a kicker with a strong enough leg (the times that Gostkowski doesn't put the ball out of the endzone it seems to be only because he's aiming simultaneously for a long hang-time -- but, if your aim is just length, hang-time doesn't matter). So, assuming that the PAT is pretty much automatic, what remains is the punt.
We know that BB favours left-footed punters with long hang times. But is that the way to go? If you aim for the sidelines, you do, of course, have to kick it somewhat farther to get the same distance advanced, but you don't have to worry about a return or hang time. I've never understood why NFL teams don't do this. So it's not impossible to negate the punt return in the same way as the kick return.
But even if you don't want to take the radical route, there's still the question of whether the entirely predictable injuries shouldn't take precedence over marginal improvements in special teams. In what season have you NOT seen Eric Alexander, Pierre Woods, James Ihedigbo, Malcolm Williams, Antwaun Molden, Derrick Martin, Nate Ebner, Tracy White, etc., etc. on the field for the Patriots in serious defensive situations? And, of course, the games where they have been asked to step up have usually been the important ones at the end of the season.
So, with all due respect to the greatest coach in the NFL, it's reasonable to ask about the relative costs and benefits of the two approaches.