Perfect Compatibility, Indeed

What are the odds of having 100% compatibility between Esper and a Guide? At least, none have been recorded in history; even above 90, it was considered a legend. 

In today's age, having 90% in wavelength compatibility was already called Perfect Compatibility and it was extremely rare. The gates had been here for over a hundred years, and the relationship between Espers and Guides was also known and established around the same time. 

That was until Rise and Kamille measured their compatibility. And in Rise's memory, it was also shockingly high, something that would create an uproar if the word got out, definitely earning several world records. 

However, it was definitely not perfect compatibility in its truest sense. It was not 100% at all, but 97%. 

The compatibility between them was only 97%, so... How come it was now 100%? What was this change? And how did it change?