In the SL Regular Rounds Leeds under McDermott:
Played 54, Won 31, Drawn 1, Lost 22, Pts For 1580, Pts Agst 1265 (Avg Scr 29-23) 58%
In percentage terms that places him somewhere between Dean Bell (44%) who inherited an impossible task and Dean Lance (59%) who had a hard act to follow in Murray and ultimately lost the dressing room and had to be replaced.
(I've used the regular rounds as an indicative measure as it eliminates favourable and/or unfavourable cup draws but others may wish to include them for the overall picture.)