You can't compare 20-30 algorithms visually without it being incredibly dense and difficult to understand. You could try:
1) Making several charts to compare a few old algorithms at a time to the new one
a) Maybe each chart contains a specific type of algorithm (I'm not familiar is but my guess is there are categories)
b) Maybe each chart is just the first three or five algorithms that haven't been compared already
2) Determine what you are using for comparison and chart that. For example, if you are comparing error over time, perhaps plot the average, maximum and minimum error for each algorithm instead.
3) Eliminate most of the algorithms before plotting. Perhaps plot only the best few and simply mention that you tested all of the others and that all resulted in worse performance than the ones in the plot. Maybe just pick a few that are most comparable to the new algorithm (like the ones that it's based on and the ones that it's most different from) to plot.