<P> The `` basket '' , an angling chain - link fence that runs along the top of the outfield wall , was installed at the start of the 1970 season . During the 1969 pennant race , there were several incidents of fans interfering with fly balls and even falling onto the field . There was also the first and only incident of a fan running the field and escaping without prosecution . A famous photograph was taken of the incident and published in the Chicago Sun - Times . The basket was intended to deter or prevent that kind of problem . Security cameras were also installed at that time . The `` basket '' angles away from the wall , and is also higher than the wall in order to provide some balance for the pitchers . However , over the years a number of baseballs have been hit `` into the basket '' for home runs that previously would have been outs , or off the wall , or possibly interfered with by fans . The basket only exists where there is seating . During the 1980s , when the bleacher seating was extended over the `` catwalks '' , i.e. the bleacher ramps in extreme left and right fields , the basket was likewise extended . </P>
<P> The `` basket '' , an angling chain - link fence that runs along the top of the outfield wall , was installed at the start of the 1970 season . During the 1969 pennant race , there were several incidents of fans interfering with fly balls and even falling onto the field . There was also the first and only incident of a fan running the field and escaping without prosecution . A famous photograph was taken of the incident and published in the Chicago Sun - Times . The basket was intended to deter or prevent that kind of problem . Security cameras were also installed at that time . The `` basket '' angles away from the wall , and is also higher than the wall in order to provide some balance for the pitchers . However , over the years a number of baseballs have been hit `` into the basket '' for home runs that previously would have been outs , or off the wall , or possibly interfered with by fans . The basket only exists where there is seating . During the 1980s , when the bleacher seating was extended over the `` catwalks '' , i.e. the bleacher ramps in extreme left and right fields , the basket was likewise extended . </P>
when was the basket installed at wrigley field
when was the basket installed at wrigley field
start of the 1970 season
start of the 1970 season