While watching Hunter Renfroe perform Monday afternoon at Petco Park, I was taken back for a moment to Mrs. Thielbaud's third grade class at Darnell Elementary.
Every morning, immediately after the Pledge of Allegiance, we'd remain standing and repeat: "Try every day in every way to be better and better."   
Watching Renfroe recently, it seems like he is living proof that there might be something to Mrs. Thielbaud's mantra.  
Almost daily, there seems to be an uptick to Renfroe's game.   
The 25-year-old rookie right fielder is still a work in progress. But you can see it coming together, which led to an interesting comment by Andy Green on Sunday morning near the end of his daily pregame media briefing.   
"There's been a noticeable change in the way he changed his at-bats," Green said of Renfroe. "That's what good players do. They adjust. This version of Hunter Renfroe has a chance to be in the outfield for a very, very long time."   
The adjustment Green was talking about came on May 6, the day after Renfroe struck out four times against the Dodgers at Petco Park. That dismal performance dropped Renfroe's batting average to .205. He had struck out 36 times in 117 at-bats while drawing two walks.   
The next day, Renfroe drew two walks off Clayton Kershaw, who wasn't walking anyone.   
Starting with that day, Renfroe has drawn 14 walks against 17 strikeouts. His batting average has climbed 33 points. His on-base percentage has climbed 70 points.  
"He made a noticeable change the day after he struck out four times," said Green.   
And plate discipline is just one area where Renfroe has improved. His throws from the outfield, while always hard, have become more accurate. His jumps on balls and routes in the outfield are improving, although he still has a ways to go on defense.   
Yes, Renfroe is still a work in progress. But he's working at it. And it shows.   
There were several instances when it showed Sunday -- resulting in the Padres 5-2 win over the reigning World Series champion Cubs at Petco Park.   
Before he hit the decisive grand slam in the bottom of the fourth to reverse a two-run Cubs lead, there was the second-inning throw from right to the plate that froze Cubs shortstop Addison Russell at third with the Cubs' third run. Russell never scored.  
That throw whistled to the plate at 101.6 mph, according to Statcast™.   
Renfroe's arm has already nailed five runners on the bases. More importantly, the word is circulating around the league that you run on Renfroe at high risk. That stops runners, like it did Russell on Monday afternoon.   
Yes, the defense is a work in progress. Renfroe already has seven errors. That is very high for an outfielder at this time of the season. But he is working on it. You can see that on the way he pursues balls into the corner.       
Renfroe has hit safely in each of his last seven starts, going 12-for-27 (.444) with four doubles, two homers, six RBIs and six runs scored.  
Five of his 10 homers have come in his last 14 starts, during which he's hit .333 (17-for-51) with eight walks -- for a .424 on-base percentage with a .745 slugging percentage for a 1.169 OPS. He also has 14 RBIs and 12 runs scored over his past 14 games.   
Renfroe also became only the second Padres player to hit two grand slams as a rookie (joining Melvin Nieves in 1995). His first came last Sept. 27 against the Dodgers.  
NOTE WORTHY    
Jarred Cosart allowed two runs on three hits and five walks in four innings Monday and left the game after four innings with a 4-2 lead. But he didn't stick around long enough to qualify for the win. Cosart has now gone 20 straight starts since Sept. 17, 2015, without getting credit with a win. It is the longest such active streak in the Major Leagues.   
Jose Torres allowed two walks with a strikeout in two scoreless innings Monday to get the win. It marked the fourth time in his last six outings that Torres has worked two innings. Since May 10, Torres has allowed three runs (two earned) on seven hits and five walks over 11 1/3 innings in nine appearances to lower his ERA from 5.52 to 3.81.   
Allen Córdoba extended his career-long hitting streak to six games by going 1-for-4 Monday. The Rule 5 Draft rookie is 9-for-26 (.345) during the streak, and his .307 batting average is now the second-highest this season by a National League rookie. Córdoba has hit safely in 13 of his last 16 games since May 9, batting .358 (19-for-53).