One goal conceded in Tottenham's first nine games this season was a very healthy return for their defensive efforts. The disorganized, almost shambolic nature of that one strike—scored by Olivier Giroud in a 1-0 defeat to Arsenal—looked to have been a mere blip given the solidity of the performances that followed.
The West Ham defeat was not solely down to failures at the back. Like with the Arsenal goal, though, the manner in which they were stretched was not encouraging—albeit it in the Hammers' last goal by a piece of individual brilliance by Ravel Morrison.
Positively this season, Villas-Boas has strove to stick with the same back four in the league, an effort that has only been undermined by Danny Rose's injury.
Yet while the tinkering that so often unsettled Spurs here last year has gone, the defense has not looked as tight as might have been hoped by now. At least not on the bigger occasions.
Michael Dawson brought much-needed leadership and a welcomed no-nonsense approach when he was restored to the team last season.
Those qualities have disconcertingly been absent in a few key moments this time around. Be it the failure to communicate sufficiently with his fellow defenders in the approach to Giroud's goal, or how he uncharacteristically allowed John Terry to run and head in Chelsea's equalizer against them unchecked.
The captain needs to up his game again, not least with Vlad Chiriches waiting his chance and the prospect of a fit Kaboul to compete with to be wary of. Dawson, though, is not alone in the responsibility of tightening things up.
Jan Vertonghen is part of the central defensive partnership. As wonderful a defender as he has proved himself again to be individually, Spurs would welcome seeing the former Ajax skipper become more commanding in regard to the overall unit.
Kyle Walker and whoever plays at left back out of Rose, Kyle Naughton and Zeki Fryers are accountable here, too.
That is the larger issue. Spurs defense are periodically strong but have not yet become the kind of consistent force together the best teams can count on.