LOUISVILLE, Ky. – Hall of Fame trainer Wayne Lukas has saddled 47 Kentucky Derby starters, winning four editions of the classic along the way. He has just one shot at his fifth Derby victory on Saturday, sending out longshot Mr. Z. However, don’t think the Lukas influence isn’t all over this Derby. Eight of the projected 20 starters are trained by Lukas or a former assistant.

LOUISVILLE, Ky. – “Rules were made to be broken.”

“There’s an exception to every rule.”

In the cliché handbook, phrases about rules aim at a demonstration of their flimsiness.

But in the Kentucky Derby, one rule approaches the status of founding principle: To win, a horse must have started as a 2-year-old.

It has been 133 years since Apollo upset the 1882 Derby. He is the last unraced 2-year-old to wear roses. Since then, 58 such horses have run in the Derby: three finished second, four third.

LOUISVILLE, Ky. – Some have compared both of Bob Baffert’s Kentucky Derby hopefuls, American Pharoah and Dortmund, to Seattle Slew, who won the Triple Crown in 1977, 38 years ago.

American Pharoah, some say, moves like Seattle Slew. Dortmund, like Seattle Slew, enters the Derby undefeated.

Jean Cruguet, the man who rode Seattle Slew, said he prefers American Pharoah to Dortmund.

As if Saturday’s championship fight between Floyd Mayweather and Manny Pacquiao needs any more publicity, along comes the aptly named Itsaknockout, who’ll provide fans one last reminder of the bout four hours before the fight starts as one of the 20 starters in this year’s Kentucky Derby.

LOUISVILLE, Ky. – Though his form suggests he will be overmatched in what looks to be one of the toughest fields in years, Keen Ice gives trainer Dale Romans a good feeling heading into Saturday’s 141st Kentucky Derby at Churchill Downs.

“He’s going to run the best race of his life,” Romans said Monday in his Churchill Downs barn office. “I’ve gotten more aggressive with him, and the mile and a quarter is going to be a huge difference.”

Effinex, the three-quarter-length winner of Saturday’s Grade 3 Excelsior Stakes, could make his next start in the Grade 2, $400,000 Brooklyn Invitational at Belmont Park on June 6 or the Grade 1, $500,000 Stephen Foster on June 13 at Churchill Downs, said Russell Cohen, racing manager for his mother Bernice’s Tri-Bone Stable.

“Whichever one is the better spot we’ll do,” Cohen said.

Effinex, a New York-bred son of Mineshaft bred by Tri-Bone, earned a career-best 107 Beyer Speed Figure for his Excelsior win. He ran the 1 1/4 miles in 2:02.16.

It is rare when an apprentice jockey wins a riding title on this circuit, but five-pound apprentice Angel Cruz did just that, taking the Aqueduct spring meet crown with 22 wins from 93 mounts.

He finished two wins in front of Irad Ortiz Jr., who went 20 for 76. Manny Franco (19 for 107), Jose Ortiz (18 for 82), and Cornelio Velasquez (14 for 92) rounded out the top five.

◗ With Larry Collmus in Louisville for Kentucky Derby week, the races during Belmont’s opening week will be called by John Imbriale.

Despite his diminished, nearly extinct relationship with Drawing Away Stable, trainer David Jacobson kept rolling, leading the trainer and owner standings in wins at Aqueduct’s winter and spring meets.

As he prepares for the Belmont spring-summer meet, which begins Wednesday, Jacobson has begun a relationship with a new client, James Costabile Jr., who is starting a claiming partnership that will race under the moniker Final Turn Stable.

LOUISVILLE, Ky. – Ken Ramsey says he was approached recently by a biographer from New York who wanted to chronicle how Ramsey has become one of the most successful people in the modern era of American racing.

“He said he wanted to call the book, ‘From the Outhouse to the Penthouse,’ ” Ramsey said with his familiar cackle. “I don’t believe he realizes how true to life that is.”

OLDSMAR, Fla. – The Tampa Bay Downs community lost one of its most respected members last week when former trainer John Reading died at age 99.

Reading’s answer to a possible midlife crisis was to retire from his position as an executive in the auto-parts industry and start a new career as a trainer in his 50s. He saddled his first horse in the mid-1960s and actively trained until 2010. He still owned runners up until 2014 and was a frequent visitor to the backstretch until recently.