generally speaking, big splits or rounds=whole log , burn long & slow & tend to smoke because of the long,slow combustion. A split will burn faster than a round because of more surface exposted to air on a split. Well seasoned wood is 1 year in the seasoning but wood seasoned only 6 months can be burned in a pinch but it is not a good thing to do as epa stoves resent poorly seasoned wood.
If you must burn pooly seasoned high moisture content wood, please mix it in with some well
seasoned, low moisture (20% moisture wood) wood so your stove can get up to the temp needed to kick in secondary burning. Without some well seasoned low moisture wood, higher temps are very hard to reach. I think you need 500 deg for secondary burn, or close to.
Should you desire to get techical about it,there are moisture meters that you can buy, they have a probe like a pot roast thremometer, but you need to drill a hole in the log to insert the probe into the log to get a reading of the moisture content of the center of the log.
I think you can read the outside or ends of the logs by just laying the probe tip on the wood but it is not so meaningful of a reading.
smaller splits burn hotter & faster & with little smoke & are usefull in getting a stove up to opperating temp fast , as well as starting the fire.
splits come in many sizes, just depends on how many times the log splitter opperator keeps cycling the splits thru the splitter.
Most firewood that you buy in winter time is not seasoned, even though the wood seller lies & says it is, so that he can pocket your money. If you dont get a reciept that says 1 year seasoned wood, you probably been had with wet & unseasoned wood.
GO TO WIKI , SEE MENU OPTION AT TOP OF PAGE & click on wiki . When wiki page comes up, look to the left hand menu & select list of wiki titles & ckick on it. This pulls up articles dealing with starting fires & wood & reconiginzing green wood vrs seasoned wood.
also ,good stuff in freq asked questions & use search engine for many threads about your question material.
REMEMBER, THE MORE YOU LEARN, THE BETTER YOU BURN
!!