[This is a compilation](http://ggweather.com/enso/oni.htm) of El Nino and La Nina ratings since the year 1950.
What I did was annotate my SOI model with the locations and weightings (strong, moderate, weak) of each of the ENSO events. The locations labelled with ? are regions that the model diverges to some extent.
For example, in 1967, the model has a stronger LaNina excursion than is identified by the historical record. Similarly, in 1980 there is a very broad LaNina excursion. From 1984 to 1986 the transition from ElNino to LaNina is delayed.
I haven't seen the identifications of LaNina/ElNino events before 1950, but looking at the model vs SOI fit, it should be an equally good match. The exception is an interval around 1945, in which the ElNino vs LaNina excursions appears 180 degrees out of-phase.