In wireless sensor network, energy efficiency is a major concern as the sensors have minimum energy capacity. As the sensor energy consumption plays a vital role in determining the network lifetime, many strategies have been proposed for energy conservation. One of them is mobile data gathering (MDG).In Mobile Data Gathering either the sink can go on tour to collect the data or a Mobile Data Collector (MDC) can collect the data from sensors and drops them back to the static sink. In this paper, static sink with mobile data collector is considered for the topic of interest. The mobile data collector will reach the cluster of sensors at some appropriate locations called as anchor points. For the formation of clusters, many algorithms have been proposed so far, two of them , Square Grid based Clustering (SGC) and Sensor Transmission based Clustering (STC) are analysed here for the selection of anchors in the anchor based mobile data gathering approach.