Search bash history for already typed command

When I type ctrl+r and *then* start typing I can see what commands in the history match which is great. Now is there a way to search the history on commands I have *already* typed in the terminal? For example if I type ctrl+r and then type ping I can cycle through servers I have pinged. But if I type "ping" first and then hit ctrl+r it ignores the "ping" I have already typed. Some times I'll get half way though typing out a string of commands and then think "oh I already typed this it sure would be nice to search the history on what I have already typed instead of starting over". Does this make sense what I am asking?