The McLaren Report Part II, released Friday, is the fourth major investigative document on Russian doping to be published in the past 13 months. All were commissioned by the World Anti-Doping Agency. All were initially prompted by whistleblowers combined with journalistic pressure rather than proactive internal questioning and probing.

Each has added a layer of understanding to the scope of centralized sabotage in Russia, where the tentacles extended from the government out onto the field of play. The country's political-athletic-industrial complex reacted to each new anti-doping initiative with the organic response of antibiotic-resistant bacteria: It mutated and persevered. More than 1,000 athletes in 30 sports have been shown to be involved so far. Every major international competition within the past five years has been compromised on a scale that exceeds even the most cynical suspicions.

There is enough revision needed to the medal standings that the International Olympic Committee really should schedule a midterm Games just to conduct fresh podium ceremonies -- assuming, that is, that the new recipients were tested as well. Because the most obvious conclusion to be drawn from the cumulatively numbing information on the table is that the current anti-doping infrastructure is far too easily gamed -- by Russia or by any individual, sport or nation with sufficient will and wile. As my British colleagues would say, it isn't "fit for purpose."

Never has the gap between cheaters and testers been so well-illuminated. As usual, that spotlight has been directed far too late to benefit any athletes who followed the rules. Such a gap is inevitable to some degree, but Russia's system also flourished because the entities that run international sport are wired to protect their own turf rather than the grass, asphalt, hardwood, ice and snow where athletes compete.

The McLaren Report revealed that there was a pass-through hole in the wall at the Sochi 2014 laboratory. EPA/Hendrik Schmidt

We'd like sports to be straightforward, and sometimes they are perversely so. Russia's motive was plain -- a piddling three gold medals in the 2010 Vancouver Winter Games -- and some tools eventually used in that service were MacGyver-esque in their simplicity: Water and salt and instant coffee to alter dirty urine samples. Coke and baby bottles to stash clean urine for future swaps. Slim strips of metal to break into supposedly tamper-proof sample bottles and a pass-through hole in the wall at the Sochi 2014 laboratory.

Much of this was previewed in Canadian law professor Richard McLaren's first report, released in July three weeks before the Rio Summer Games to some controversy because of reliance on testimony from former Moscow lab director Grigory Rodchenkov.

Rodchenkov, who first described his experience to the New York Times last spring, adroitly played both sides of the fence, developing the science for better detection of steroid use while simultaneously crafting the methodology to beat it. (Friday's report also states Rodchenkov moonlighted as a Russian federal secret agent.) This is a meme often repeated in sports doping, where research can serve dark and light purposes equally well.

McLaren Part II turned to forensic evidence to see if Rodchenkov's claims could be substantiated. The professor notes that many witnesses are still reluctant to cooperate because of fears for their safety, and many urine samples remain beyond his reach, long since destroyed or sealed up in the Moscow lab by Russian investigators, a label that should be an oxymoron by now.

However, the testing McLaren was able to commission, and the correspondence and data lifted from Rodchenkov's hard drive, revealed enough to corroborate Part I of the report.

There wasn't always enough clean or altered urine to switch for dirty samples. DNA testing showed that urine from different athletes was mixed. Russia's most prominent athletes were placed on protected lists from the start, their samples automatically misreported as negative in the databases of the Moscow lab and WADA, or earmarked for swapping at competitions. The women's hockey team was elevated to that status on the eve of the Sochi Games, but equality of treatment in Russia's national game proved elusive. Execution was sloppy. Male DNA found its way into two of their urine samples.

At that point, Russia had gotten away with so much that it seemed unlikely that would ever surface.

Isolated attempts to expose the system were ignored, shelved or undermined until it was no longer possible to do so, as was the case with the whistleblowing Stepanovs. McLaren highlights another example that is just as glaring in retrospect: The December 2012 email sent by discus thrower Darya Pishchalnikova straight to the WADA database, addressed to the presidents of the IOC, WADA and IAAF, track and field's governing body.

The text of the email is included in the hundreds of pages of evidence posted by McLaren's team on a searchable website. It's unclear whether wording is original or translated, but its content is unmistakable: Pishchalnikova, an Olympic silver medalist, had been busted. She didn't think it was fair, and she pointed the powers that be toward what she knew about bribery and sample-swapping.

It's hard to parse whether she was being heroic or vindictive or both, but that doesn't really matter. There was no chance her tip was going to be pursued. Subsequent events have implicated the IAAF in the cover-up. Neither WADA -- which already had two-plus years of damning correspondence from Vitaly Stepanov at that point -- nor the IOC wanted any part of lifting the curtain. Soon enough, Pishchalnikova was suspended by her own federation.