Originally Posted by Fredd

We found this USA Today article interesting, particularly this excerpt:

Understand how TripAdvisor's rankings work.

The biggest factor in determining a property's popularity ranking is the number of recent reviews — which helps explain how a hotel like New York's Hotel Casablanca, which has only 48 rooms but generates an average of one review a day vs. the Manhattan average of four per month, can climb to No. 1 in the city.

Conversely, while older reviews remain posted unless a hotel can prove a change in management, they have less impact on a hotel's popularity ranking over time, says Kaufer.

It appears that the four most recent reviews for this property are from September onward.

FWIW we discount TA reviews if there are fewer than 10-20, especially if the reviewers are brand new TA members. In the case of the property the OP mentions, several members are new but three or more have contributed to TA for some time, so we'd simply take the totality of the reviews with a grain of salt. YMMV.