David Moyes lamented Sunderland's inability to defend crosses as Romelu Lukaku's hat trick guided Everton to a 3-0 win at the Stadium of Light on Monday.
Sunderland extended their run without a Premier League league victory in August or September to 23 games dating back to 2012.
"If there are things that we have done, it is we have worked on defending crosses and being in the right positions, but we certainly didn't show it tonight," Moyes said.
"We didn't stop the crosses, didn't defend the crosses, didn't get in the right positions when they did come in.