Crapp was a senior player with Carlton in the VFA between 1885 and 1890. He is listed as a member of the Carlton VFA side 10 times during 1890, his final year; the last time being in round 12 (August 2, 1890) against South Melbourne at the MCG. During the last 6 games of that season he was listed in the final squad of 23 players (with 20 players making up the side, the exact make-up of the team is unknown in each case).
Putting aside his nickname of 'Ivo', to which we have no background, Crapp is also sometimes referred to in the press of the time as Harry (a similar concept to utilisation of the name ‘Jack’ for those with a christian name of ‘John’).
In 1893, two brothers named Crapp also played for Carlton (a W and an H. Crapp), but neither is considered to have been our 'Ivo'. Details are scarce but it would seem a high probability that both brothers were related to 'Ivo'.
A few years later, it would seem that ‘Ivo’ had begun his career as an umpire in the Victorian Football Association, but when the newly formed Victorian Football League was formed in 1897, Crapp obviously swapped over as well. In fact, he was appointed to the first match at Corio Oval between Geelong and Essendon.
His VFA and VFL career extended to 147 matches between 1897 and 1905, which included 17 finals and 7 Grand Finals (1898, 1899, 1900, 1901, 1902, 1904, 1905). 43 of these 147 matches were those of the Carlton Football Club, although students of Carlton’s history would notice that our only Grand Final of that lot was 1905, which was our first, but unsuccessful. Sniggers from opposition fans can carefully be put aside, as it was the subsequent year in which Carlton would win their first VFL premiership, when Carlton defeated Fitzroy by 49 points.
Incidentally, Crapp laid the first ever report in the VFL in Round 7, 1898 when he reported St. Kilda's Bill Matthews for "bad language." At the tribunal hearing Matthews was found guilty and reprimanded. This was the only umpires' report in the first two seasons of the VFL.
Amongst many other achievements, Crapp is credited in a match between Melbourne and Fitzroy in 1901 as being the first umpire to not only call the reasons for free kicks to players, but also to nominate by name who was to take them.
Crapp also became something of a teacher for future Umpires. Henry ‘Bunny’ Nugent, a famed Umpire and Australian ANZAC, once famously noted:
“Following Ivo Crapp from game to game, I noted his style and one day plucked up enough courage to ask him what one needed in his make-up to be a successful umpire. He told me, 'Get yourself into first class condition, learn the rules thoroughly and be fearless and prompt with your decisions'. I have lived up to this advice as far as possible. As an honorary umpires' advisor to the VJFA, I always passed on the words of the old master."
After 1905, Crapp then went to WA and umpired there for a number of years. He umpired 51 round games (30 consecutive 1906 to 1914) and 10 Grand Finals (1906-1914, 1918).