HERC first got into rap in 1979 upon hearing "Rapper's Delight" at the wrap party for his Eighth Grade class play. Billboard didn't formerly recognize the format with a chart until an entire decade later when they rolled out the Hot Rap Singles chart in the March 11, 1989 issue. Flash forward twenty-five years and two name changes later, and we have the Hot Rap Songs chart celebrating its quarter-century anniversary.
For this list of the Top 100 songs during those first twenty-five years according to Billboard:
"rankings are based on an inverse point system, with weeks at No. 1 having the greatest value and weeks at lower positions proportionately less. Due to various changes in chart rules, chart length and methodology throughout the years, songs had varying reigns at No. 1 and on the chart. To ensure equitable representation of the biggest hits from all 25 years, certain time frames were weighted to account for the difference in turnover rates from those periods."