Claim: Steffi Graf plays tennis professionally.
Evidence: Stefanie Maria `` Steffi '' Graf -LRB- -LSB- ˈʃtɛfiː ˈgʁa : f -RSB- ; born 14 June 1969 -RRB- is a German former tennis player , who was ranked world No. 1 during her career.
The list of WTA number 1 ranked players shows the professional women 's tennis players who have been or currently are ranked world No. 1 by the Women 's Tennis Association , along with the dates of first reaching and losing that spot.