tip-ex.com has a scalp calculator under "Odds Comparison" then "Menu 2".
Click on the books you wish to check
Click on the leagues you wish to check
Select the radio circle next to "Sure Wins"
Type in the minimum return (1.00 = 100%)
Click "Send"
But for Americans we are limited to the books we can use.
Here is the result for 100% for Monday (1.01 would guarantee a 1% return on your scalp):
<TABLE class="ocbase ocsw"><TBODY><TR><TD class=swg colSpan=2>FBDEN 2. Div West-09</TD><TR><TD class=swt>01-06-2009</TD><TD class=swp>
Næsby-OB Odense II</TD><TR><TD colSpan=2><TABLE class=swmtable><TBODY><TR><TD class=swe>1.01</TD><TD class=swb>Betfair (4.40)</TD><TD class=swb>Betfair (4.60)</TD><TD class=swb>Nordicbet (1.83)</TD><TR><TD class=swe>1.00</TD><TD class=swb>5 Dimes (4.31)</TD><TD class=swb>Betfair (4.60)</TD><TD class=swb>Nordicbet (1.83)</TD><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (4.40)</TD><TD class=swb>5 Dimes (4.50)</TD><TD class=swb>Nordicbet (1.83)</TD><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (4.40)</TD><TD class=swb>Unibet (4.50)</TD><TD class=swb>Nordicbet (1.83)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE><TABLE class="ocbase ocsw"><TBODY><TR><TD class=swg colSpan=2>FBNOR Tippeligaen-09</TD><TR><TD class=swt>01-06-2009</TD><TD class=swp>
Stabæk-Tromsø</TD><TR><TD colSpan=2><TABLE class=swmtable><TBODY><TR><TD class=swe>1.00</TD><TD class=swb>Stan James (1.95)</TD><TD class=swb>betliner (3.85)</TD><TD class=swb>Betfair (4.40)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE><TABLE class="ocbase ocsw"><TBODY><TR><TD class=swg colSpan=2>FBNOR Tippeligaen-09</TD><TR><TD class=swt>01-06-2009</TD><TD class=swp>
Viking-Vålerenga</TD><TR><TD colSpan=2><TABLE class=swmtable><TBODY><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (2.18)</TD><TD class=swb>Betfair (3.60)</TD><TD class=swb>Nordicbet (3.85)</TD><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (2.18)</TD><TD class=swb>Nordicbet (3.60)</TD><TD class=swb>Nordicbet (3.85)</TD><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (2.18)</TD><TD class=swb>betliner (3.57)</TD><TD class=swb>Nordicbet (3.85)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE><TABLE class="ocbase ocsw"><TBODY><TR><TD class=swg colSpan=2>FBNOR Adeccoligaen-09</TD><TR><TD class=swt>01-06-2009</TD><TD class=swp>
Skeid-Løv-Ham</TD><TR><TD colSpan=2><TABLE class=swmtable><TBODY><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (2.84)</TD><TD class=swb>Betfair (3.75)</TD><TD class=swb>Unibet (2.65)</TD><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (2.84)</TD><TD class=swb>Betfair (3.75)</TD><TD class=swb>Stan James (2.63)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE><TABLE class="ocbase ocsw"><TBODY><TR><TD class=swg colSpan=2>FBICE Premier-09</TD><TR><TD class=swt>01-06-2009</TD><TD class=swp>
IB Vestmannäyjar-Grindavik</TD><TR><TD colSpan=2><TABLE class=swmtable><TBODY><TR><TD class=swe>1.00</TD><TD class=swb>Betfair (2.40)</TD><TD class=swb>Betfair (3.55)</TD><TD class=swb>Expekt (3.35)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE><TABLE class="ocbase ocsw"><TBODY><TR><TD class=swg colSpan=2>FBICE Premier-09</TD><TR><TD class=swt>01-06-2009</TD><TD class=swp>
Keflavak-Stjarnan F.C.</TD><TR><TD colSpan=2><TABLE class=swmtable><TBODY><TR><TD class=swe>1.01</TD><TD class=swb>Expekt (1.80)</TD><TD class=swb>Betfair (4.20)</TD><TD class=swb>Betsson Sportsbook (5.00)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>