This is a tragic post mate. Parker finishes Artur brutally and you'd know doubt think the same if Spilka wasn't known for outboxing Wilder for 2/3 of their fight before being brutally KO'd in highlight reel fashion.
The thing is, things change quickly in the boxing world. If you look at the facts he's only officially lost 2 fights. He actually did pretty well against Joshua, despite what people say. I thought he won 4 rounds and went the distance which no one else could. He was certainly impeded by the referee. He was unfortunate against Whyte, (who he nearly stopped at the end), really unfortunate (with the headbutt and the scoring) and Whyte's win over Parker is largely why he (Whyte) is currently regarded as the #4 heavyweight by many people. It's crazy that such a narrow and dubious result makes Whyte some sort of hot property right now but Parker is written off as a done deal almost. He definitely has lost momentum and may need a couple of fights to re-buiild confidence. In terms of technical ability it is impossible to know whether he is improving still or not. I think it would be a major turnaround if he were ever to rise to the #1 position. That would signal remarkable improvement. But he's arguably still well within reach of a place in the top 3 or 4. In fact, if Whyte is #4 now, Parker is arguably still #5. Anything can happen. There are a whole bunch of guys with a degree of 'name' recognition - Parker, Povetkin, Whyrte, Pulev , Ortiz etc. - who can conceivably win or lose against each other and move forward or back. And Parker, being younger than all of them named, is actually in a better position than the rest in terms of chances.