Try:

  history | sed 's/|/\n1 /' | awk '{print $2}' | sort | uniq -c | sort -rn | head -n 100

Of course this doesn't differentiate between quoted pipes and ones actually being used.

The ‘awk’ there effectively still drops everything after the second limiter, i.e. you won’t get a different result.

Edit:

    history | sed -e 's/^ *[0-9]*  //' -e 's/| */\n/'  | awk '{print $1}' | sort | uniq -c | sort -rn | head -n 100

works for me.

Yeah I just realized that. Fixed.

Excellent point. I'm definitely going to put that caveat at the beginning of any analysis I post. (and thanks to ctrl_freak for posting an alternative!)