The Fighting Chance Universe

"So, how bad is it Admiral Cole?"
"Bad, Admiral Sugihara. The Covenant have a notable range advantage over us and the Post-Penetration effects of their plasma weapons are absolutely horrific. To say nothing of the durability of that monster's energy shields which absorbed excessive punishment from our warships before failing. Thankfully the hull armor doesn't have the same durability."
"How are we going to survive this war as a species if the deck is this stacked against us?"
"Simple ma'am, we improvise, adapt, and overcome; necessity is the mother of invention, war is its father. I've asked my damage control officers about how we could improve the formulas of our armor and test its effectiveness against plasma. They recommended using a plasma torch for testing new armor compositions. Additionally, I requested that UNSCS Cradle report to Harvest, we are going to salvage the wreck of that ship in its entirety, take it Reach and analyze the absolute hell out of it and learn everything we can from it. Smashed shield generators and emitters while worthless to them, could give us pointers on how to create our own energy shield systems, the computers while severely damaged, we might be able to extract fragments of navigational data from them or if we're lucky, fragments of what used to be the shipboard AI, and finally the Slipspace Drive could make our ships faster in FTL and reduce our error of probability when we exit SF Space. We have a chance admiral, a fighting one, but we need fight smart and use all of our available resources to our advantage in order to have that fighting chance. They claim that our extermination is the will of their gods, it sure as hell isn't the will of our gods. They want to exterminate humanity and our extinction is pre-ordained by the cruel whims of fate? I say let's give them a bloody nose that they shall never forget then."
"Your right admiral, we must use everything to our advantage. The shock of the Covenant invasion along with so many dead and a CMA Task Force butchered, I just-" 
"It's alright ma'am, the Covenant came as a shock to everyone and what they did to Harvest, its population, and what they want to do to the rest of humanity. Let's honor them, remember them, and avenge them."
- Vice Admiral Preston J. Cole and CNO Fleet Admiral Sugihara Ryu after the former's official debriefing about Second Battle of Harvest, July 12th, 2526.
The Fighting Chance Universe is set primarily during the Human-Covenant War years, which for the conflict proper lasts from 2525 to 2553, with the Post-War conflicts lasting for decades after. This universe follows canon with most changes involved in this universe having commonsense to make the UNSC be able to actually fight a 27-year long war without things like ship production being outstripped almost immediately by ship losses nor resource losses being as catastrophic. Now, the death spiral will happen as systems as lost to the Covenant onslaught and they will be lost. 
== Primary Differences ==
Most of the differences in The Fighting Chance Universe compared to canon are primarily in the economics department, however changes regarding Common Sense also occur as well; along with notably some injection of realism in regards to vehicle dimensions. 
The economic changes primarily relate to the declaration of Total War by the UEG at the start of the Human-Covenant War. The very survival of the human race is at hand, fighting with one hand tied behind your back isn't an option. Every aspect of the UEG's economy and industry go towards fighting the alien menace and ensuring the survival of the human race. This means that the already impressive industrial might of the UEG, which can crank out a Halcyon class Cruiser in four years will become even more impressive as production capacity grows and whatnot. 
The common sense aspect here is that the UNSC is always working to improve its weapons, armor, powerplants etc. throughout the course of the war. With most of these improvements coming from the fact that the UNSC here will salvage the wrecks of Covenant Warships, often sending Prowlers out after a battle is done to wait until the Covenant depart, then calling for something like UNSCS Cradle to appear and then salvage the largest wrecks, then in-accordance with Subsection 7 of the Cole Protocol, the wrecks are swept then hauled away to a place like Reach where they are then ripped apart until they reveal their secrets. 
The final part is that some UNSC vehicles -most of the ground vehicles actually barring stuff like Warthogs and more specialized vehicles like the Elephant and Mammoth- are of a more realistic size mostly to make maneuvering them in the relatively cramped confines of a starship plausible without needing overly large specialized corridors or the tight confines of streets as well as making it easier for Pelican and Condor Dropships carrying these vehicles to be modified to carry them from Space and down through the atmosphere to the ground in order to deliver vehicles safely without needing an Assault Ship or Transport to skim or enter atmosphere if there are Surface-to-Orbit emplacements around.